U.S. patent number 8,110,709 [Application Number 10/576,282] was granted by the patent office on 2012-02-07 for stabilization of hydroformylation catalysts based on phosphoramide ligands.
This patent grant is currently assigned to BASF SE. Invention is credited to Wolfgang Ahlers, Thomas Mackewitz, Rocco Paciello, Rainer Papp, Martin Volland.
United States Patent |
8,110,709 |
Papp , et al. |
February 7, 2012 |
Stabilization of hydroformylation catalysts based on phosphoramide
ligands
Abstract
The present invention relates to a process for the
hydroformylation of ethylenically unsaturated compounds by reaction
with carbon monoxide and hydrogen in the presence of a
catalytically active fluid which comprises a dissolved metal
complex of a metal of transition group VIII of the Periodic Table
of the Elements with at least one phosphoramidite compound as
ligand, wherein the fluid is brought into contact with a base.
Inventors: |
Papp; Rainer (Speyer,
DE), Ahlers; Wolfgang (Worms, DE),
Mackewitz; Thomas (Romerberg, DE), Paciello;
Rocco (Bad Durkheim, DE), Volland; Martin
(Heidelberg, DE) |
Assignee: |
BASF SE (Ludwigshafen,
DE)
|
Family
ID: |
34484948 |
Appl.
No.: |
10/576,282 |
Filed: |
October 22, 2004 |
PCT
Filed: |
October 22, 2004 |
PCT No.: |
PCT/EP2004/011986 |
371(c)(1),(2),(4) Date: |
April 19, 2006 |
PCT
Pub. No.: |
WO2005/039762 |
PCT
Pub. Date: |
May 06, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060224000 A1 |
Oct 5, 2006 |
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Foreign Application Priority Data
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Oct 23, 2003 [DE] |
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103 49 343 |
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Current U.S.
Class: |
568/454; 564/12;
564/14; 548/412; 568/451 |
Current CPC
Class: |
C07C
45/50 (20130101); B01J 31/186 (20130101); C07C
45/50 (20130101); C07C 47/02 (20130101); B01J
2231/321 (20130101); B01J 2531/822 (20130101); B01J
2531/0238 (20130101) |
Current International
Class: |
C07C
45/50 (20060101); C07F 9/572 (20060101); C07F
9/06 (20060101) |
Field of
Search: |
;564/14,12 ;548/412
;568/451,454 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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10206697 |
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Aug 2002 |
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DE |
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10256164 |
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Jun 2003 |
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DE |
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10342760 |
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Mar 2004 |
|
DE |
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0183199 |
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Jun 1986 |
|
EP |
|
0149894 |
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Mar 1989 |
|
EP |
|
0276231 |
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Oct 1991 |
|
EP |
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0214622 |
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May 1992 |
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EP |
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0155508 |
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Dec 1992 |
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EP |
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WO-97/20794 |
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Jun 1997 |
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WO |
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WO-97/20795 |
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Jun 1997 |
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WO |
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WO-97/20796 |
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Jun 1997 |
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WO |
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WO-97/20797 |
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Jun 1997 |
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WO |
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WO-97/20798 |
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Jun 1997 |
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WO |
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WO-97/20799 |
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Jun 1997 |
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WO |
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WO-97/20800 |
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Jun 1997 |
|
WO |
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WO-97/33854 |
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Sep 1997 |
|
WO |
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WO-00/56451 |
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Sep 2000 |
|
WO |
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WO-02/083695 |
|
Oct 2002 |
|
WO |
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WO-03/018192 |
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Mar 2003 |
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WO |
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WO-03/070679 |
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Aug 2003 |
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WO |
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WO-2004/078766 |
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Sep 2004 |
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WO |
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Other References
Oxford Dictionary of Biochemistry and Molecular Biology Rev. Ed.,
Smith, A.D., 1997, Oxford University Press, p. 504. cited by
examiner .
Organic Chemistry, 4th Ed., McMurry, J., Brooks/Cole Publishing
Co., p. 1161. cited by examiner .
Phosphorus an Outline of its Chemistry, Biochemistry and Uses,
Fifth Ed. Corbridge, D.E.C. Elsevier, p. 407. cited by examiner
.
Jackstell et al. Eur. J. Org. Chem. 2001, 3871-3877. cited by
examiner .
van Leeuwen in Chapter 9 of Catalysis by Metal Complexes, vol. 22,
Rhodium Catalyzed Hydroformylation, 2002, Kluwer Acad. Pub., pp.
233-251. cited by examiner .
Moloy et al. J. Am. Chem. Soc. 1995, 117, 7696-7710. cited by
examiner .
Xu et al. Tetrahedron Lett. 1997, 38(42), 7337-7340. cited by
examiner .
Anna M. Trzeciak et al., "Novel rhodium complexes with
N-pyrrolylphosphines: attractive precursors of hydroformylation
catalysts", J. Chem. Soc., Dalton Trans., 1997, pp. 1831-1837.
cited by other .
International Search Report No. PCT/EP2004/011986, dated Dec. 22,
2004, 8 pages. cited by other.
|
Primary Examiner: Nolan; Jason M
Attorney, Agent or Firm: Connolly Bove Lodge & Hutz
LLP
Claims
The invention claimed is:
1. A process for the hydroformylation of compounds which comprises,
providing at least one compound with an ethylenically unsaturated
double bond and reacting the at least one compound with carbon
monoxide and hydrogen in at least one reaction zone in the presence
of a catalytically active fluid which comprises a dissolved metal
complex of a metal of transition group VIII of the Periodic Table
of the Elements with at least one phosphoramidite compound as
ligand, wherein the fluid is brought into contact with at least one
base selected from trialkyl amines, dialkyaryl amines, alkyldiaryl
amines, triaryl amines, and bases immobilized on a solid phase, or
a combination thereof, and wherein the phosphoramidite compound is
selected from among compounds of the formulae I and II ##STR00021##
where R.sup.1 and R.sup.5 are each, independently of one another,
pyrrole groups bound via the nitrogen atom to the phosphorus atom,
R.sup.2, R.sup.3 and R.sup.4 are each, independently of one
another, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, or
R.sup.1 together with R.sup.2 and/or R.sup.4 together with R.sup.5
forms a divalent group containing at least one pyrrole group bound
via the pyrrolic nitrogen atom to the phosphorus atom, Y is a
divalent bridged group having from 2 to 20 bridge atoms between the
flanking bonds, X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are selected
independently from among O, S, SiR.sup..alpha.R.sup..beta.and
NR.sup..gamma., where R.sup..alpha., R.sup..beta.and
R.sup..gamma.are each, independently of one another, hydrogen,
alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, and a, b, c
and d are each, independently of one another, 0 or 1.
2. A process according to claim 1, further comprising removing from
the reaction zone a product mixture which is subjected to a
fractionation to give a fraction consisting essentially of a
hydroformylation product and a fraction comprising the
catalytically active fluid in which the by-products of the
hydroformylation which have boiling points higher than that of the
hydroformylation product are present and the metal complex is
dissolved, and recirculating the catalytically active fluid to the
reaction zone.
3. A process according to claim 1, wherein the at least one base is
selected from bases soluble in the catalytically active fluid,
bases immobilized on a solid phase or combinations thereof.
4. A process according to claim 1, wherein the base comprises a
basic nitrogen.
5. A process according to claim 1, wherein the at least one base is
soluble in the catalytic fluid and is present in a molar ratio of
base to phosphoramidite compound of from 0.01:1 to 5:1, in the
reaction zone.
6. A process according to claim 1, wherein the at least one base
includes a base soluble in the catalytic fluid and a base
immobilized on a solid phase and the immobilized base is capable of
at least partly liberating the soluble base from acid-base adducts
obtained by reaction of the soluble base with an acid.
7. A process according to claim 2, wherein the fractionation of the
product mixture comprises a thermal separation step and at least
one high-boiling soluble base remains in the catalytically active
fluid after the fractionation.
8. A process according to claim 2, wherein at least one base
immobilized on a solid phase is used and the catalytically active
fluid obtained after fractionation is brought into contact with the
immobilized base before it is recirculated to the reaction
zone.
9. A process according to claim 1, wherein the phosphoramidite
compound is selected from among compounds of the formula II.1
##STR00022## where R.sup.1 and R.sup.5 are each, independently of
one another, pyrrole groups bound via the nitrogen atom to the
phosphorus atom, R.sup.2 and R.sup.4 are each, independently of one
another, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, or
R.sup.1 together with R.sup.2 and/or R.sup.4 together with R.sup.5
forms a divalent group containing at least one pyrrole group bound
via the pyrrolic nitrogen atom to the phosphorus atom, Y is a
divalent bridged group having from 2 to 20 bridge atoms between the
flanking bonds, and b and c are each, independently of one another,
0 or 1.
10. A process according to claim 1, wherein R.sup.1, R.sup.2,
R.sup.4 and R.sup.5 are selected independently from among groups of
the formulae III.a to III.k ##STR00023## where Alk is a
C.sub.1-C.sub.12-alkyl group and R.sup.a, R.sup.b, R.sup.c and
R.sup.d are each, independently of one another, hydrogen,
C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-alkoxy, acyl, halogen,
C.sub.1-C.sub.4-alkoxycarbonyl or carboxyl.
11. A process according to claim 1, wherein the bridging group Y is
selected from among groups of the formulae IV.a to IV.u
##STR00024## ##STR00025## ##STR00026## where R.sup.I, R.sup.I',
R.sup.II, R.sup.II', R.sup.III, R.sup.III', R.sup.IV, R.sup.IV',
R.sup.V, R.sup.VI, R.sup.VII, R.sup.VIII, R.sup.IX, R.sup.X,
R.sup.XI and R.sup.XII are each independently of one another,
hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl,
hydroxy, thiol, polyalkylene oxide, polyalkylenimine, alkoxy,
halogen, SO.sub.3H, sulfonate, NE.sup.1E.sup.2,
alkylene-NE.sup.1E.sup.2, nitro, alkoxycarbonyl, carboxyl, acyl or
cyano, where E.sup.1 and E.sup.2 are identical or different
radicals selected from among hydrogen, alkyl, cycloalkyl and aryl,
Z is O, S, NR.sup..delta. or SiR.sup..delta.R.sup..epsilon., where
R.sup..delta. and R.sup..epsilon. are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, or Z is a C.sub.1-C.sub.4-alkylene bridge which may have a
double bond and/or bear an alkyl, cycloalkyl, heterocycloalkyl,
aryl or hetaryl substituent, or Z is a C.sub.1-C.sub.4-alkylene
bridge which may have a double bond and/or bear an alkyl,
cycloalkyl, heterocycloalkyl, aryl or hetaryl substituent, or Z is
a C.sub.2-C.sub.4-alkylene bridge which is interrupted by O, S or
NR.sup..delta. or SiR.sup..delta.R.sup..epsilon., where, in the
groups of the formulae IV.a and IV.b, two adjacent radicals R.sup.I
to R.sup.VI together with the carbon atoms of the benzene ring to
which they are bound may also form a fused ring system having 1, 2
or 3 further rings, where, in the groups of the formulae IV.h to
IV.n, two geminal radicals R.sup.I, R.sup.I'; R.sup.II, R.sup.II';
R.sup.III, R.sup.III' and/or R.sup.IV, R.sup.IV'' may also
represent oxo or a ketal thereof, A.sup.1 and A.sup.2 are each,
independently of one another, O, S, SiR.sup..phi.R.sup..gamma.,
NR.sup..eta. or CR.sup.R.sup..kappa., where
R.sup..phi.,R.sup..gamma., R.sup..eta., R.sup. and R.sup..kappa.
are each, independently of one another, hydrogen, alkyl,
cycloalkyl, heterocycloalkyl, aryl or hetaryl, A.sup.3 and A.sup.4
are each, independently of one another, SiR, N or CR.sup., D is a
divalent bridging group of the formula ##STR00027## where R.sup.9,
R.sup.9', R.sup.10 and R.sup.10' are each, independently of one
another, hydrogen, alkyl, cycloalkyl, aryl, halogen,
trifluoromethyl, carboxyl, carboxylate or cyano, where R.sup.9'
together with R.sup.10' can also represent the second bond of a
double bond between the two carbon atoms to which R.sup.9' and
R.sup.10' are bound, and/or R.sup.9 and R.sup.10 together with the
carbon atoms to which they are bound may also form a 4- to
8-membered carbocycle or heterocycle which may additionally be
fused with one, two or three cycloalkyl, heterocycloalkyl, aryl or
hetaryl groups, where the heterocycle and, if present, the fused-on
groups may each bear, independently of one another, one, two, three
or four substituents selected from among alkyl, cycloalkyl,
heterocycloalkyl, aryl, hetaryl, COOR.sup.f, COO.sup.-M.sup.+,
SO.sub.3R.sup.f, SO.sup.-.sub.3M.sup.+, NE.sup.4E.sup.5,
alkylene-NE.sup.4E.sup.5, NE.sup.4E.sup.5E.sup.6+X.sup.-,
alkylene-NE.sup.4E.sup.5E.sup.6+X.sup.-, OR.sup.f, SR.sup.f,
(CHR.sup.eCH.sub.2O).sub.yR.sup.f,
(CH.sub.2N(E.sup.4)).sub.yR.sup.f,
(CH.sub.2CH.sub.2N(E.sup.4)).sub.yR.sup.f, halogen,
trifluoromethyl, nitro, acyl and cyano, where R.sup.f, E.sup.4,
E.sup.5 and E.sup.6 are identical or different radicals selected
from among hydrogen, alkyl, cycloalkyl and aryl, R.sup.e is
hydrogen, methyl or ethyl, M.sup.+ is a cation, is an anion and y
is an integer from 1 to 240.
12. A process according to claim 2 further comprising removing at
least part of the by-products from the catalytically active fluid
prior to recirculating the fluid.
13. A process according to claim 5, wherein the molar ratio is from
0.1:1 to 1.5:1.
14. A process according to claim 9, wherein R.sup.1, R.sup.2,
R.sup.4 and R.sup.5 are selected independently from among groups of
the formulae III.a to III.k ##STR00028## ##STR00029## where Alk is
a C.sub.1-C.sub.12-alkyl group and R.sup.a, R.sup.b, R.sup.c and
R.sup.d are each, independently of one another, hydrogen,
C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-alkoxy, acyl, halogen,
C.sub.1-C.sub.4-alkoxycarbonyl or carboxyl.
15. A process according to claim 9, wherein the bridging group Y is
selected from among groups of the formulae IV.a to IV.u
##STR00030## ##STR00031## ##STR00032## where R.sup.I, R.sup.I',
R.sup.II, R.sup.II', R.sup.III, R.sup.III', R.sup.IV, R.sup.IV',
R.sup.V, R.sup.VI, R.sup.VII, R.sup.VIII, R.sup.IX, R.sup.X,
R.sup.XI and R.sup.XII are each, independently of one another,
hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl,
hydroxy, thiol, polyalkylene oxide, polyalkylenimine, alkoxy,
halogen, SO.sub.3H, sulfonate, NE.sup.1E.sup.2,
alkylene-NE.sup.1E.sup.2, nitro, alkoxycarbonyl, carboxyl, acyl or
cyano, where E.sup.1 and E.sup.2 are identical or different
radicals selected from among hydrogen, alkyl, cycloalkyl and aryl,
Z is O, S, NR.sup..delta. or SiR.sup..delta.R.sup..epsilon., where
R.sup..delta. and R.sup..epsilon. are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, or Z is a C.sub.1-C.sub.4-alkylene bridge which may have a
double bond and/or bear an alkyl, cycloalkyl, heterocycloalkyl,
aryl or hetaryl substituent, or Z is a C.sub.2-C.sub.4-alkylene
bridge which is interrupted by O, S or NR.sup..delta. or
SiR.sup..delta.R.sup..epsilon., where, in the groups of the
formulae IV.a and IV.b, two adjacent radicals R.sup.Ito R.sup.VI
together with the carbon atoms of the benzene ring to which they
are bound may also form a fused ring system having 1, 2 or 3
further rings, where, in the groups of the formulae IV.h to IV.n,
two geminal radicals R.sup.I, R.sup.I'; R.sup.II, R.sup.II';
R.sup.III, R.sup.III' and/or R.sup.IV, R.sup.IV'' may also
represent oxo or a ketal thereof, A.sup.1 and A.sup.2 are each,
independently of one another, O, S, SiR.sup..phi.R.sup..gamma.,
NR.sup..eta. or CR.sup.R.sup..kappa., where R.sup..phi.,
R.sup..gamma., R.sup..eta., R.sup. and R.sup..kappa. are each,
independently of one another, hydrogen, alkyl, cycloalkyl,
heterocycloalkyl, aryl or hetaryl, A.sup.3 and A.sup.4 are each,
independently of one another, SiR, N or CR.sup., D is a divalent
bridging group of the formula ##STR00033## where R.sup.9, R.sup.9',
R.sup.10 and R.sup.10' are each, independently of one another,
hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl,
carboxyl, carboxylate or cyano, where R.sup.9' together with
R.sup.10' can also represent the second bond of a double bond
between the two carbon atoms to which R.sup.9' and R.sup.10' are
bound, and/or R.sup.9 and R.sup.10 together with the carbon atoms
to which they are bound may also form a 4- to 8-membered carbocycle
or heterocycle which may additionally be ffsed with one, two or
three cycloalkyl, heterocycloalkyl, aryl or hetaryl groups, where
the heterocycle and, if present, the fused-on groups may each bear,
independently of one another, one, two, three or four substituents
selected from among alkyl, cycloalkyl, heterocycloalkyl, aryl,
hetaryl, COOR.sup.f, COO.sup.-M.sup.+, SO.sub.3R.sup.f,
SO.sup.-.sub.3M.sup.+, NE.sup.4E.sup.5, alkylene-NE.sup.4E.sup.5,
NE.sup.4E.sup.5E.sup.6+X.sup.-,
alkylene-NE.sup.4E.sup.5E.sup.6+X.sup.-, OR.sup.f, SR.sup.f,
(CHR.sup.eCH.sub.2O).sub.yR.sup.f,
(CH.sub.2N(E.sup.4)).sub.yR.sup.f,
(CH.sub.2CH.sub.2N(E.sup.4)).sub.yR.sup.f, halogen,
trifluoromethyl, nitro, acyl and cyano, where R.sup.f, E.sup.4,
E.sup.5 and E.sup.6 are identical or different radicals selected
from among hydrogen, alkyl, cycloalkyl and aryl, R.sup.e is
hydrogen, methyl or ethyl, M.sup.+ is a cation, is an anion and y
is an integer from 1 to 240.
16. A process according to claim 10, wherein the bridging group Y
is selected from among groups of the formulae IV.a to IV.u
##STR00034## ##STR00035## ##STR00036## where R.sup.I, R.sup.I',
R.sup.II, R.sup.II', R.sup.III, R.sup.III', R.sup.IV, R.sup.IV',
R.sup.V, R.sup.VI, R.sup.VII, R.sup.VIII, R.sup.IX, R.sup.X,
R.sup.XI and R.sup.XII are each, independently of one another,
hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl,
hydroxy, thiol, polyalkylene oxide, polyalkylenimine, alkoxy,
halogen, SO.sub.3H, sulfonate, NE.sup.1E.sup.2,
alkylene-NE.sup.1E.sup.2, nitro, alkoxycarbonyl, carboxyl, acyl or
cyano, where E.sup.1 and E.sup.2 are identical or different
radicals selected from among hydrogen, alkyl, cycloalkyl and aryl,
Z is O, S, NR.sup..delta. or SiR.sup..delta.R.sup..epsilon., where
R.sup..delta. and R.sup..epsilon. are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, or Z is a C.sub.1-C.sub.4-alkylene bridge which may have a
double bond and/or bear an alkyl, cycloalkyl, heterocycloalkyl,
aryl or hetaryl substituent, or Z is a C.sub.2-C.sub.4-alkylene
bridge which is interrupted by O, S or NR.sup..delta. or
SiR.sup..delta.R.sup..epsilon., where, in the groups of the
formulae IV.a and IV.b, two adjacent radicals R.sup.Ito R.sup.VI
together with the carbon atoms of the benzene ring to which they
are bound may also form a fused ring system having 1, 2 or 3
further rings, where, in the groups of the formulae IV.h to IV.n,
two geminal radicals R.sup.I, R.sup.I'; R.sup.II, R.sup.II';
R.sup.III, R.sup.III' and/or R.sup.IV, R.sup.IV'' may also
represent oxo or a ketal thereof, A.sup.1 and A.sup.2 are each,
independently of one another, O, S, SiR.sup..phi.R.sup..gamma.,
NR.sup..eta. or CR.sup.R.sup..kappa., where R.sup..phi.,
R.sup..gamma., R.sup..eta., R.sup. and R.sup..kappa. are each,
independently of one another, hydrogen, alkyl, cycloalkyl,
heterocycloalkyl, aryl or hetaryl, A.sup.3 and A.sup.4 are each,
independently of one another, SiR, N or CR.sup., D is a divalent
bridging group of the formula ##STR00037## where R.sup.9, R.sup.9',
R.sup.10 and R.sup.10' are each, independently of one another,
hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl,
carboxyl, carboxylate or cyano, where R.sup.9' together with
R.sup.10' can also represent the second bond of a double bond
between the two carbon atoms to which R.sup.9' and R.sup.10' are
bound, and/or R.sup.9 and R.sup.10 together with the carbon atoms
to which they are bound may also form a 4- to 8-membered carbocycle
or heterocycle which may additionally be fused with one, two or
three cycloalkyl, heterocycloalkyl, aryl or hetaryl groups, where
the heterocycle and, if present, the fuised-on groups may each
bear, independently of one another, one, two, three or four
substituents selected from among alkyl, cycloalkyl,
heterocycloalkyl, aryl, hetaryl, COOR.sup.f, COO.sup.-M.sup.+,
SO.sub.3R.sup.f, SO.sup.-.sub.3M.sup.+, NE.sup.4E.sup.5,
alkylene-NE.sup.4E.sup.5, NE.sup.4E.sup.5E.sup.6+X.sup.-,
alkylene-NE.sup.4E.sup.5E.sup.6+X.sup.-, OR.sup.f, SR.sup.f,
(CHR.sup.eCH.sub.2O).sub.yR.sup.f,
(CH.sub.2N(E.sup.4)).sub.yR.sup.f,
(CH.sub.2CH.sub.2N(E.sup.4)).sub.yR.sup.f, halogen,
trifluoromethyl, nitro, acyl and cyano, where R.sup.f, E.sup.4,
E.sup.5 and E.sup.6 are identical or different radicals selected
from among hydrogen, alkyl, cycloalkyl and aryl, R.sup.e is
hydrogen, methyl or ethyl, M.sup.+ is a cation, is an anion and y
is an integer from 1 to 240.
17. A process for the hydroformylation of compounds which
comprises, providing at least one compound with an ethylenically
unsaturated double bond and reacting the at least one compound with
carbon monoxide and hydrogen in at least one reaction zone in the
presence of a catalytically active fluid which comprises a
dissolved metal complex of a metal of transition group VIII of the
Periodic Table of the Elements with at least one phosphoramidite
compound as ligand, wherein the fluid is brought into contact with
at least one base selected from trialkyl amines, dialkyaryl amines,
alkyldiaryl amines, and triaryl amines, and wherein the
phosphoramidite compound is selected from among compounds of the
formulae I and II ##STR00038## where R.sup.1 and R.sup.5 are each,
independently of one another, pyrrole groups bound via the nitrogen
atom to the phosphorus atom, R.sup.2, R.sup.3 and R.sup.4 are each,
independently of one another, alkyl, cycloalkyl, heterocycloalkyl,
aryl or hetaryl, or R.sup.1 together with R.sup.2 and/or R.sup.4
together with R.sup.5 forms a divalent group containing at least
one pyrrole group bound via the pyrrolic nitrogen atom to the
phosphorus atom, Y is a divalent bridged group having from 2 to 20
bridge atoms between the flanking bonds, X.sup.1, X.sup.2, X.sup.3
and X.sup.4 are selected independently from among O, S,
SiR.sup..alpha.R.sup..beta.and NR.sup..gamma., where R.sup..alpha.,
R.sup..beta.and R.sup..gamma.are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, and a, b, c and d are each, independently of one another,
0 or 1, further comprising removing from the reaction zone a
product mixture which is subjected to a fractionation to give a
fraction consisting essentially of a hydroformylation product and a
fraction comprising the catalytically active fluid in which the
by-products of the hydroformylation which have boiling points
higher than that of the hydroformylation product are present and
the metal complex is dissolved, and recirculating the catalytically
active fluid to the reaction zone.
18. The process according to claim 17, wherein the recirculating of
the catalytically active fluid is carried out in the absence of
carbon monoxide and hydrogen.
19. A method of stabilizing a catalytically active fluid comprising
a dissolved metal complex of a metal of transition group VIII of
the Periodic Table of the Elements with at least one
phosphoramidite compound as ligand in the hydroformylation of
ethylenically unsaturated compounds, which comprises bringing the
fluid into contact with at least one base selected from trialkyl
amines, dialkyaryl amines, alkyldiaryl amines, triaryl amines, and
bases immobilized on a solid phase, or a combination thereof,
wherein the at least one phosphoramidite compound is selected from
among compounds of the formulae I and II ##STR00039## where R.sup.1
and R.sup.5 are each, independently of one another, pyrrole groups
bound via the nitrogen atom to the phosphorus atom, R.sup.2,
R.sup.3 and R.sup.4 are each, independently of one another, alkyl,
cycloalkyl, heterocycloalkyl, aryl or hetaryl, or R.sup.1 together
with R.sup.2 and/or R.sup.4 together with R.sup.5 forms a divalent
group containing at least one pyrrole group bound via the pyrrolic
nitrogen atom to the phosphorus atom, Y is a divalent bridged group
having from 2 to 20 bridge atoms between the flanking bonds,
X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are selected independently
from among O, S, SiR.sup..alpha.R.sup..beta.and NR.sup..gamma.,
where R.sup..alpha., R.sup..beta.and R.sup..gamma.are each,
independently of one another, hydrogen, alkyl, cycloalkyl,
heterocycloalkyl, aryl or hetaryl, and a, b, c and d are each,
independently of one another, 0 or 1.
20. A method according to claim 19, wherein base is soluble in the
catalytically active fluid and/or the fluid is brought into contact
with a base immobilized on a solid phase.
Description
CROSS REFERENCE TO RELATED APPLICATION
The present application is a National Stage application of
PCT/EP2004/011886, filed Oct. 22, 2004, which claims priority from
German Patent Application No. DE 103 49 343.3, filed Oct. 23,
2003.
DESCRIPTION
The present invention relates to a process for the hydroformylation
of ethylenically unsaturated compounds by reaction with carbon
monoxide and hydrogen in the presence of a catalytically active
fluid which comprises a dissolved metal complex of a metal of
transition group VIII of the Periodic Table of the Elements with at
least one phosphoramidite compound as ligand, wherein the fluid is
brought into contact with a base.
Hydroformylation or the oxo process is an important industrial
process and is employed for preparing aldehydes from olefins,
carbon monoxide and hydrogen. These aldehydes can, if desired, be
hydrogenated by means of hydrogen in the same process to give the
corresponding oxo alcohols. The reaction itself is strongly
exothermic and generally proceeds under superatmospheric pressure
and at elevated temperatures in the presence of catalysts.
Catalysts used are Co, Rh, Ir, Ru, Pd or Pt compounds or complexes
which may be modified by means of N- or P-containing ligands to
influence the activity and/or selectivity. In the hydroformylation
reaction of olefins having more than two carbon atoms, the
formation of mixtures of isomeric aldehydes can occur due to the
possible CO addition onto each of the two carbon atoms of a double
bond. In addition, double bond isomerization, i.e. a shift of
internal double bonds to a terminal position and vice versa, can
also occur when using olefins having at least four carbon
atoms.
Owing to the significantly greater industrial importance of
.alpha.-aldehydes, optimization of the hydroformylation catalysts
to achieve a very high hydroformylation activity and at the same
time a very low tendency to form olefins having double bonds which
are not in the .alpha. position is desirable. In addition, there is
a need for hydroformylation catalysts which lead to good yields of
.alpha.- and in particular n-aldehydes even when linear internal
olefins are used as starting materials. Here, the catalyst has to
make possible both the establishment of an equilibrium between
internal and terminal double bond isomers and the very selective
hydroformylation of the terminal olefins.
WO 00/56451 describes hydroformylation catalysts based on
phosphinamidite ligands in which the phosphorus atom together with
an oxygen atom to which it is bound forms a 5- to 8-membered
heterocycle.
WO 02/083695 describes chelating pnicogen compounds in which at
least one pyrrole group is bound via the pyrrole nitrogen to each
of pnicogen atoms. These chelating pnicogen compounds are suitable
as ligands for hydroformylation catalysts.
WO 03/018192 describes, inter alia, pyrrole-phosphorus compounds in
which at least one pyrrole group which is substituted and/or
integrated into a fused ring system is covalently bound via its
pyrrole nitrogen to the phosphorus atom, which display a very good
stability when used as ligands in hydroformylation catalysts.
The German patent application 102 43 138.8, which is not a prior
publication, describes pnicogen compounds which have two pnicogen
atoms and in which pyrrole groups can be bound via a pyrrole
nitrogen to both pnicogen atoms and both pnicogen atoms are bound
via a methylene group to a bridging group. These pnicogen compounds
are suitable as ligands for hydroformylation catalysts.
The abovementioned catalysts display a high regioselectivity to
terminal product aldehydes both in the hydroformylation of
.alpha.-olefins and in the hydroformylation of internal linear
olefins. In addition, they have a good stability under the
hydroformylation conditions, particularly in the case of
hydroformylation catalysts based on ligands in which one or more
3-alkylindole group(s) is/are bound to the phosphorus atom.
Nevertheless, additional stabilization is desirable with a view to
the long catalyst lives required for large-scale industrial
use.
DE-A-102 06 697 describes a hydroformylation process which makes it
possible for the products of value to be separated off and the
catalyst to be recirculated with a very low loss of activity. This
is achieved using a hydroformylation catalyst based on a bidentate
phosphine ligand which is stabilized by at least one monodentate
phosphine ligand.
EP-A-0 149 894 and U.S. Pat. No. 4,567,306 describe a continuous
hydroformylation process using a hydroformylation catalyst which
has a cyclic phosphite having a phosphorus atom as bridge head as
ligand. Three oxygen atoms are bound directly to the phosphorus
atom and at least two of these form a ring together with the
phosphorus atom. Suitable ligands have, for example, a
phosphabicyclo[2.2.2]octane or phosphaadamantyl skeleton. The
process includes the stabilization of the ligands by means of a
tertiary amine.
EP-A-0 155 508 and U.S. Pat. No. 4,599,206 describe
hydroformylation processes using catalyst complexes based on
diorganophosphite ligands, in which a liquid output can be taken
from the reaction zone, brought into contact with a weak base anion
exchanger and subsequently returned to the reaction zone. U.S. Pat.
No. 4,717,775 describes a variant of the hydroformylation process
disclosed in the abovementioned documents, according to which the
hydroformylation is carried out in the presence of free
diorganophosphite ligand. U.S. Pat. No. 4,774,361 describes a
process for avoiding or minimizing the precipitation of rhodium
from rhodium-phosphite catalyst complexes in a hydroformylation
process having a liquid circuit, in which the aldehyde is distilled
off from the reaction mixture and this distillation is carried out
in the presence of an organic polymer containing at least three
polar amide functions, for example polyvinylpyrrolidone or
copolymers of vinylpyrrolidone and vinyl acetate. EP-A-0 276 231
has a disclosure content comparable to U.S. Pat. No. 4,774,361.
EP-A-214 622 describes a hydroformylation process using a catalyst
based on a polyphosphite ligand which has from two to six phosphite
groups. It is stated that the polyphosphite ligands can be
stabilized if necessary by bringing the liquid output from the
reaction zone into contact with a weak base anion-exchange resin
before or after the product aldehydes have been separated off and
only then recirculating the stream to the hydroformylation
reactor.
WO 97/20794 and U.S. Pat. No. 5,741,942 describe methods of
separating acidic phosphorus compounds from a reaction liquid
comprising a metal-organophosphite catalyst complex and, if
desired, free organophosphite ligands by treating the reaction
liquid with an aqueous buffer solution which is able to remove at
least part of the acidic phosphorus compounds. It is possible to
use an additional organic nitrogen compound which is capable of
reacting with the acidic phosphorus compounds, with the reaction
product of nitrogen compound and phosphorus compound likewise being
neutralized and removed by treatment with the aqueous buffer
solution. Methods of stabilizing organophosphite ligands against
hydrolytic degradation, of stabilizing metal-organophosphite
catalyst complexes against deactivation and of reacting one or more
reactants in the presence of metal-organophosphite catalyst
complexes, in each of which a treatment with an aqueous buffer
solution is carried out, have also been described. U.S. Pat. No.
5,741,944 describes an analogous method of separating acidic
phosphorus compounds from hydroformylation product mixtures. U.S.
Pat. No. 5,874,640 describes an analogous method of removing acidic
phosphorus compounds from reaction product mixtures comprising
metal catalyst complexes with organophosphorus ligands in general.
Application of the method to reaction solutions containing
phosphoramidite ligands is not described.
WO 97/20795, U.S. Pat. Nos. 5,741,943 and 5,741,945 describe
processes which comprise reacting one or more reactants in the
presence of a metal-organopolyphosphite catalyst complex and, if
desired, free organopolyphosphite ligand and another, different
sterically hindered organophosphorus ligand. The latter has the
function of an indicator ligand which indicates depletion of the
reaction mixture in polyorganophosphite ligands and at the same
time is supposed to keep the rhodium in solution in the case of
such a depletion.
WO 97/20797, U.S. Pat. Nos. 5,744,649 and 5,786,517 describe
methods of removing acidic phosphorus compounds from reaction
liquids comprising metal-organophosphite catalyst complexes by
treatment with water. U.S. Pat. No. 5,886,235 describes an
analogous method of treating reaction liquids which comprise metal
complexes based on organophosphorus ligands as catalysts in quite
general terms.
WO 97/20798 and U.S. Pat. No. 5,731,472 describe methods of
stabilizing metal-organopolyphosphite catalyst complexes against
deactivation, in which the catalyzed reaction is carried out in the
presence of at least one free, heterocyclic nitrogen compound
selected from among diazoles, triazoles, diazines and
triazines.
WO 97/20799, U.S. Pat. Nos. 5,763,671 and 5,789,625 relate to
methods of removing acidic phosphorus compounds from reaction
liquids comprising metal-organophosphite catalyst complexes by
extraction with water and treatment of the water with an
acid-removing substance. U.S. Pat. No. 5,917,095 relates to an
analogous method in which metal complexes based on organophosphorus
ligands in general are used as catalysts.
WO 97/20800, U.S. Pat. Nos. 5,763,670 and 5,767,321 relate to
processes in which organopolyphosphite catalyst complexes are used
in the presence of a sufficient amount of free organopolyphosphite
ligand to prevent or reduce hydrolytic degradation of the ligand
and deactivation of the catalyst.
WO 97/20796, U.S. Pat. Nos. 5,763,677 and 5,763,680 describe
methods of separating one or more acidic phosphorus compounds from
reaction liquids comprising metal-organophosphite catalyst
complexes by extraction with water and treatment of the water with
an ion exchanger and optionally an amine. U.S. Pat. No. 5,892,119
describes an analogous method for reaction liquids which comprise
metal complexes based on organophosphorus ligands in general as
catalysts. Treatment of reaction liquids comprising catalysts based
on phosphoramidite ligands is not described.
It is an object of the present invention to provide an improved
process for the hydroformylation of compounds containing at least
one ethylenically unsaturated double bond. It should use
hydroformylation catalysts which make it possible for relatively
long-chain, terminal or internal olefins or industrial mixtures of
olefins having terminal and internal double bonds, e.g. mixtures of
1-butene and 2-butene, to be hydroformylated to give good yields of
aldehydes having a higher linearity (n selectivity). A further
requirement which the hydroformylation catalysts have to meet is
good stability under hydroformylation conditions and thus a long
catalyst operating life, since catalyst or ligand losses have a
particularly adverse effect on the economics of a hydroformylation
process.
It has now surprisingly been found that this object is achieved by
a hydroformylation process in which a metal complex of a metal of
transition group VIII of the Periodic Table of the Elements with at
least one phosphoramidite compound as ligand dissolved in the
reaction medium is used to catalyze the reaction and in which the
solution is brought into contact with a base.
The invention accordingly provides a process for the
hydroformylation of compounds containing at least one ethylenically
unsaturated double bond by reaction with carbon monoxide and
hydrogen in at least one reaction zone in the presence of a
catalytically active fluid which comprises a dissolved metal
complex of a metal of transition group VIII of the Periodic Table
of the Elements with at least one phosphoramidite compound as
ligand, wherein the fluid is brought into contact with a base.
BRIEF DESCRIPTIONS OF THE DRAWINGS
FIG. 1 shows a miniplant for carrying out continuous
hydroformylations consisting of two autoclaves with lifting stirrer
connected in series (1 and 2), a pressure separator (3), a flash
stripping column (4), and an ion exchanger bed (5).
FIG. 2 shows a miniplant for carrying out continuous
hydroformylations. This consists of two autoclaves with lifting
stirrer connected in series (1 and 2), a pressure separator (3), a
heated depressurization vessel for separating off
C.sub.4-hydrocarbons (4), a wiped film evaporator (5), and an ion
exchanger bed (6).
For the purposes of the present invention, a "phosphoramidite
compound" is a phosphorus-containing compound having at least one
phosphorus atom to which one, two or three groups are covalently
bound via a nitrogen atom, i.e. to form a P--N bond.
Phosphoramidite compounds, in particular those in which one or more
substituted pyrrole groups are bound via their nitrogen atom to the
phosphorus atom, and the hydroformylation catalysts based on them
are known to have a good stability. The inventors of the present
invention have now found that catalysts based on phosphoramidite
ligands can be additionally stabilized against degradation of the
ligands or deactivation of the catalysts under hydroformylation
conditions by bringing the catalytically active fluid into contact
with a base. This is surprising since these ligands already contain
more or less basic nitrogen-containing groups. Advantageously,
stabilization of the hydroformylation catalysts based on
phosphoramidite ligands by bringing them into contact with a base
is successful even in the absence of synthesis gas. The present
invention therefore also provides a hydroformylation process
comprising the work-up of the output from the reaction zone and
recirculation of the catalytically active fluid, with at least one
of these steps being carried out in the absence of carbon monoxide
and hydrogen.
For the purposes of the present invention, "bringing into contact"
refers both to formation of a single-phase mixture and to
contacting via a phase interface, e.g. liquid/liquid or
liquid/solid. The contacting can be carried out over the total
duration of the hydroformylation (including the work-up and
recirculation of the catalytically active fluid), part thereof or
periodically.
The catalytically active fluid comprises at least one dissolved
metal complex of a metal of transition group VIII of the Periodic
Table of the Elements with at least one phosphoramidite compound as
ligand. The metal complex is thus generally present as a
homogeneous single-phase solution in a suitable solvent. This
solution can further comprise phosphoramidite compounds as free
ligands. As solvents, preference is given to using the relatively
high-boiling subsequent reaction products formed in the
hydroformylation of the respective ethylenically unsaturated
compounds, e.g. the products of aldol condensation. Furthermore,
the hydroformylation products can also function as solvents until
they are separated off.
Aromatics such as toluene and xylenes, hydrocarbons or mixtures of
hydrocarbons are likewise suitable as solvents. Further suitable
solvents are esters of aliphatic carboxylic acids with alkanols,
for example ethyl acetate or Texanol.RTM., ethers such as
tert-butyl methyl ether and tetrahydrofuran. In the case of
sufficiently hydrophilic ligands, it is also possible to use
alcohols such as methanol, ethanol, n-propanol, isopropanol,
n-butanol, isobutanol, ketones such as acetone and methyl ethyl
ketone, etc. Furthermore, "ionic liquids" can also be used as
solvents. These are liquid salts, for example
N,N'-dialkylimidazolium salts such as N-butyl-N'-methylimidazolium
salts, tetraalkylammonium salts such as tetra-n-butylammonium
salts, N-alkylpyridinium salts such as n-butylpyridinium salts,
tetraalkylphosphonium salts such as
trishexyl(tetradecyl)phosphonium salts, e.g. the
tetrafluoroborates, acetates, tetrachloroaluminates,
hexafluorophosphates, chlorides and tosylates.
The hydroformylation is carried out in at least one reaction zone
which can comprise one or more, identical or different reactors. In
the simplest case, the reaction zone is formed by a single reactor.
Both the reactors of each individual zone and the reactors which
may form different stages can in each case have identical or
different mixing characteristics. The reactors can, if desired, be
divided one or more times by means of internals. If two or more
reactors form one zone, these can be connected in any desired way,
e.g. in parallel or in series.
Suitable pressure-rated reaction apparatuses for the
hydroformylation are known to those skilled in the art. They
include the generally customary reactors for gas-liquid reactions,
e.g. tube reactors, stirred vessels, gas circulation reactors,
bubble columns, etc., which may, if appropriate, be divided by
internals.
Carbon monoxide and hydrogen are usually used in the form of a
mixture known as synthesis gas. The composition of the synthesis
gas used in the process of the invention can vary within a wide
range. The molar ratio of carbon monoxide to hydrogen is generally
from 1:1000 to 1000:1, preferably from 1:100 to 100:1. If a
plurality of reaction zones are used, these can have identical or
different molar ratios of CO to H.sub.2.
The temperature in the hydroformylation reaction is generally in
the range from about 20 to 200.degree. C., preferably from about 50
to 190.degree. C., in particular from about 60 to 150.degree. C.
The reaction is preferably carried out at a pressure in the range
from about 1 to 700 bar, particularly preferably from 3 to 600 bar,
in particular from 5 to 50 bar. The reaction pressure can be varied
as a function of the activity of the hydroformylation catalyst
used. Thus, the hydroformylation catalysts described in more detail
below sometimes allow a reaction in a lower pressure range, for
instance in the range from about 1 to 100 bar. If a plurality of
reaction zones are used, these can be operated at identical or
different temperatures and/or pressures.
The hydroformylation can be carried out batchwise or continuously.
Preference is given to a continuous process wherein a) the
ethylenically unsaturated compound(s) and carbon monoxide and
hydrogen are fed into the reaction zone(s) and are reacted in the
presence of the catalytically active fluid, b) an output is taken
from the reaction zone and is subjected to a fractionation to give
a fraction consisting essentially of the hydroformylation product
and a fraction comprising the catalytically active fluid in which
the by-products of the hydroformylation which have boiling points
higher than that of the hydroformylation product are present and
the metal complex is dissolved, and c) the catalytically active
fluid is, if appropriate after separating off at least part of the
by-products having boiling points higher than that of the
hydroformylation product, recirculated to the reaction zone.
The output from the reaction zone is subjected to a single-stage or
multistage separation operation to give a stream comprising the
major part of the hydroformylation product and a stream comprising
the catalytically active fluid. Depending on the discharge and
separation methods employed, further streams are generally
obtained, e.g. offgases comprising synthesis gas, streams
comprising unreacted ethylenically unsaturated compound with or
without saturated hydrocarbon etc. These can be recirculated partly
or in their entirety to the reaction zone or be discharged from the
process.
Preference is given to taking a liquid output from the reaction
zone (liquid discharge process). This liquid output comprises, as
significant constituents: i) the hydroformylation product, i.e. the
aldehydes produced from the olefin or olefin mixture used, ii) the
high-boiling by-products of the hydroformylation, as result from,
for example, the aldol reaction of the aldehydes formed, iii) the
homogeneously dissolved hydroformylation catalyst and possibly free
ligand, iv) possibly unreacted olefins, v) low-boiling components
such as alkanes, and vi) dissolved synthesis gas.
If an inert solvent is used for the hydroformylation, this is also
present in the liquid output from the reaction zone. However, the
by-products which are formed in the hydroformylation (e.g. by aldol
condensation) and have boiling points higher than that of the
hydroformylation product are generally used as solvent.
The fractionation of the liquid output from the reaction zone to
give firstly a fraction consisting essentially of the
hydroformylation product and, secondly, the catalytically active
fluid in which the by-products of the hydroformylation which have
boiling points higher than that of the hydroformylation product are
present and the metal complex is dissolved is carried out by
conventional methods known to those skilled in the art. These
include depressurization and thermal fractionation steps
(distillations). Suitable separation apparatuses for a distillation
are, for example, distillation columns such as tray columns which
may, if desired, be equipped with bubble caps, sieve plates, sieve
trays, valves, etc., evaporators such as thin film evaporators,
falling film evaporators, wiped film evaporators, etc.
The liquid output from the reaction zone can, for example, be
worked up by firstly subjecting it to a single-stage or multistage
degassing operation.
In one embodiment with single-stage degassing, the liquid output
from the reaction zone is, for example, depressurized into a
depressurization vessel and, as a result of the reduction in
pressure, the output is separated into a liquid phase comprising
the hydroformylation catalyst and, if present, free ligands, the
high-boiling by-products of the hydroformylation and a gaseous
phase comprising the major part of the hydroformylation product
formed, any unreacted olefins, low-boiling components and excess
synthesis gas. The liquid phase forming the catalytically active
fluid can, in order to recycle the catalyst, be returned as a
recycle stream, if appropriate after separating off at least part
of the high-boiling by-products, to the reaction zone. The gas
phase can be worked up further by passing it to, for example, a
condenser in which the hydroformylation product is separated off in
liquid form. The gas phase obtained in the condenser, which
consists essentially of unreacted synthesis gas, unreacted olefin
and inert components, can, if appropriate after separating off at
least part of the inert components, be returned either wholly or
partly to the reaction zone.
In a further embodiment of the liquid discharge process with
degassing, the liquid output from the reaction zone is worked up by
subjecting to a two-stage degassing operation. Here, the first
degassing stage can also be configured as a calming zone in which
no gas is introduced into the liquid phase. The gas phase obtained
in this calming/depressurization stage consists essentially of
synthesis gas. The liquid phase obtained from the
calming/depressurization stage can in turn be separated into a
liquid phase and a gas phase in a second depressurization stage
(degassing stage). The second liquid phase obtained in this way
generally comprises the by-products having boiling points higher
than that of the hydroformylation product, the homogeneously
dissolved first hydroformylation catalyst and possibly part of the
hydroformylation product. The second gas phase comprises the
unreacted olefin, saturated hydrocarbons and likewise part of the
hydroformylation product. To isolate firstly the catalytically
active fluid and secondly a fraction comprising the major part of
the hydroformylation product, the second depressurization stage can
be followed by a thermal work-up. This thermal separation step can
be, for example, a distillation. In the distillation, the second
liquid phase and the second gas phase from the second
depressurization step are preferably conveyed in countercurrent and
thus brought into particularly intimate contact (stripping). In a
preferred embodiment, the second depressurization stage is
configured as a combination of the depressurization step (flash)
with a thermal separation step (flash/stripping stage).
As an alternative to the above-described pure liquid discharge
processes, it is also possible to use the gas recycle process in
which a further gaseous output is taken from the gas space of the
reaction zone. This gaseous output consists essentially of
synthesis gas, unreacted olefins and inert components, and,
depending on the vapor pressure of the hydroformylation product in
the reaction zone, part of the hydroformylation products formed may
also be discharged in this gaseous output. The hydroformylation
product carried out with the gas stream can be condensed out by,
for example, cooling and the gas stream which has been freed of the
liquid fraction can be returned to the reaction zone.
The bases used in the process of the invention are preferably
selected from among bases soluble in the catalytically active
fluid, bases immobilized on a solid phase and combinations thereof.
The base is preferably selected from among basic nitrogen
compounds.
Particularly preferred bases are nitrogen compounds which have no
primary and secondary nitrogen atoms (i.e. ones to which H atoms
are still bound). Basic nitrogen compounds which contain compounds
having primary and secondary nitrogen atoms as impurities, e.g.
tertiary amines which are, as a result of the method by which they
are produced, contaminated with primary and/or secondary amines,
can be subjected to a work-up to remove at least part of these
compounds before they are used in the process of the invention.
Suitable bases are, for example, trialkylamines. Trialkylamines
which have a boiling point below or in the region of that of the
product aldehydes, as is generally the case for
tri(C.sub.1-C.sub.3-)alkylamines, are less suitable if the product
aldehydes are separated from the reaction product mixture by
distillation.
Preference is also given to the base being selected from among
dialkylarylamines, preferably di(C.sub.1-C.sub.4-)alkylarylamines,
where the alkyl groups and/or the aryl group may be substituted
further. The aryl group is preferably phenyl. Such compounds
include, for example, N,N-dimethylaniline, N,N-diethylaniline,
N,N,2,4,6-pentamethylaniline,
bis(4-(N,N-dimethylamino)phenyl)methylene,
4,4'-bis(N,N-dimethylamino)benzo-phenone, etc.
Preference is also given to the base being selected from among
alkyldiarylamines, preferably (C.sub.1-C.sub.4-)alkyldiarylamines,
where the alkyl group and/or the aryl group may be substituted.
Such compounds include, for example, diphenylmethylamine and
diphenylethylamine.
Preference is also given to the base being selected from among
triarylamines, where the aryl groups may be substituted, for
example triphenylamine, etc. Further preferred amines are
tricycloalkylamines, such as tricyclohexylamine.
Preference is also given to the base being selected from among
nitrogen-containing heterocycles. The nitrogen-containing
heterocycles are preferably selected from the group consisting of
pyrroles, pyrrolidines, pyridines, quinolines, isoquinolines,
purines, pyrazoles, imidazoles, triazoles, tetrazoles, indolizines,
pyridazines, pyrimidines, pyrazines, triazines, indoles,
isoindoles, oxazoles, oxazolidones, oxazolidines, morpholines,
piperazines, piperidines and derivatives thereof.
Suitable derivatives of the abovementioned nitrogen-containing
heterocycles can have, for example, one or more
C.sub.1-C.sub.6-alkyl substituents such as methyl, ethyl, n-propyl,
isopropyl, n-butyl, sec-butyl, tert-butyl, etc.
Heterocycles preferred as bases are pyrroles, indoles, pyridines,
quinolines and triazoles, which may additionally bear one or more
C.sub.1-C.sub.6-alkyl substituents. Such compounds include, for
example, 3-alkylindoles, such as 3-methylindole,
2,6-dialkylpyridines, such as 2,6-dimethylpyridine, quinoline and
1-H-benzotriazole.
The abovementioned bases can be used either individually or in the
form of any mixtures.
When at least one base which is soluble in the catalytically active
fluid is used, a molar ratio of base to phosphoramidite compound of
from 0.01:1 to 5:1, preferably from 0.1:1 to 1.5:1, is preferably
maintained in the reaction zone. For this purpose, for example, the
pH of the reaction mixture can be monitored at regular intervals
and base can be added to the reaction mixture if necessary.
If the work-up of the reaction output encompasses, as described
above, a thermal separation step, preference is given to using
high-boiling soluble bases which have a boiling point under the
conditions of the thermal work-up which is sufficiently above those
of the hydroformylation products. The output from the reaction zone
is preferably fractionated so that the resulting fraction
comprising the hydroformylation product is essentially free of the
base used. The fractionation of the output from the reaction zone
is preferably also carried out so that essentially all the base is
present in the fraction forming the catalytically active fluid and
is recirculated to the reaction zone together with this.
In one embodiment of the process of the invention, at least one
base immobilized on a solid phase is used as base. Suitable
immobilized bases are in principle the basic ion exchangers known
to those skilled in the art. The solid phase of these basic ion
exchangers comprises, for example, a polymer matrix. Such matrices
include, for example, polystyrene matrices which comprise
copolymers of styrene and at least one crosslinking monomer, e.g.
divinylbenzene, together with, if appropriate, further comonomers.
Further suitable matrices are polyacrylic matrices obtained by
polymerization of at least one (meth)acrylate, at least one
crosslinking monomer and, if appropriate, further comonomers.
Suitable polymer matrices also include phenol-formaldehyde resins
and polyalkylamine resins which are obtained, for example, by
condensation of polyamines with epichlorohydrin.
The anchor groups which are bound to the solid phase either
directly or via a spacer group (and whose loosely bound counterions
can be replaced by ions bearing a charge of the same sign) are
preferably selected from among nitrogen-containing groups,
preferably tertiary and quaternary amino groups. Preference is
given to anchor groups which are present in the free base form.
Examples of suitable functional groups are (in order of decreasing
basicity): --CH.sub.2N.sup.+(CH.sub.3).sub.3OH.sup.-e.g. Duolite A
101 --CH.sub.2N.sup.+(CH.sub.3).sub.2CH.sub.2CH.sub.2OH
OH.sup.-e.g. Duolite A 102 --CH.sub.2N(CH.sub.3).sub.2 e.g.
Amberlite IRA 67 --CH.sub.2NHCH.sub.3 --CH.sub.2NH.sub.2 e.g.
Duolite A 365
Both strongly basic and weakly basic ion exchangers are suitable
for the process of the invention, with preference being given to
weakly basic ion exchangers. Among weakly basic ion exchangers,
preference is given to those containing tertiary amino groups.
Strongly basic ion exchangers generally have quaternary ammonium
groups as anchor groups. A weakly basic ion exchanger is generally
present in the free base form after regeneration.
Commercially available ion exchangers suitable for the process of
the invention are, for example, Amberlite.RTM. IRA 67 and Amberlyst
A21.
Ion exchangers usually have a hydrophilic sphere of bound water.
The bases immobilized on a solid phase are preferably brought into
contact with at least one anhydrous solvent to remove part or all
of the bound water before they are used in the process of the
invention. In such a case, preference is given to firstly treating
the ion exchanger with a water-soluble or water-miscible solvent
and subsequently with an essentially water-insoluble solvent.
Suitable water-miscible solvents are, for example, alcohols such as
methanol, ethanol, n-propanol, isopropanol etc. Suitable
essentially water-insoluble solvents are, for example, aromatics
such as toluene and xylenes, hydrocarbons and hydrocarbon mixtures
and also high-boiling alcohols, e.g. 2-propylheptanol. It has
surprisingly been found that the ion exchangers used according to
the invention are also suitable for stabilizing phosphoramidite
compounds against degradation or protecting the corresponding
hydroformylation catalysts from deactivation in an essentially
water-free medium.
The catalytically active fluid is preferably brought into contact
with an immobilized base by taking a liquid output from the
reaction zone and bringing it into contact with the immobilized
base before or after it is fractionated. Preference is given to the
fraction forming the catalytically active fluid which is obtained
by fractionation of the output being brought into contact with the
immobilized base. The base can be present either in the form of a
slurry or in the form of packing, e.g. as a fixed bed.
The regeneration of the immobilized base is carried out by
conventional methods known to those skilled in the art, e.g.
treatment with aqueous base. Suitable bases are, for example,
ammonium, alkali metal carbonates such as sodium carbonate and
potassium carbonate, and alkali metal hydroxides such as sodium
hydroxide and potassium hydroxide. Preference is given to firstly
carrying out the treatment with one of the abovementioned
water-soluble or water-miscible solvents before regeneration.
Regeneration is preferably followed by at least one rinsing step
using a dry organic solvent, as described above. Here too,
particular preference is given to firstly carrying out a treatment
with a water-soluble or water-miscible solvent and subsequently
with an essentially water-insoluble solvent.
In a preferred embodiment of the process of the invention, a
combination of at least one base soluble in the catalytic fluid and
at least one base immobilized on a solid phase is used. The base
pairs are selected so that the immobilized bases are capable of at
least partly liberating the soluble bases from the acid-base
adducts obtained by reaction of the soluble bases with acids. For
this purpose, the bases are selected so that the base strengths of
the liquid bases under the reaction conditions are lower than the
base strengths of the immobilized bases. These base strengths can
readily be determined by a person skilled in the art by means of
simple routine experiments. A good guide is provided by the
pK.sub.b values for the bases which are generally known for use in
aqueous systems.
Phosphoramidite compounds suitable for use in the process of the
invention are described in WO 00/56451, WO 02/083695, WO 03/018192
and the German patent application 102 43 138.8, which are hereby
fully incorporated by reference.
The metal of transition group VIII of the Periodic Table is
preferably Co, Ru, Rh, Pd, Pt, Os or Ir, especially Rh, Co, Ir or
Ru.
In the following, the expression "alkyl" encompasses straight-chain
and branched alkyl groups. The alkyl groups are preferably
straight-chain or branched C.sub.1-C.sub.20-alkyl groups, more
preferably C.sub.1-C.sub.12-alkyl groups, particularly preferably
C.sub.1-C.sub.8-alkyl groups and very particularly preferably
C.sub.1-C.sub.4-alkyl groups. Examples of alkyl groups are, in
particular, methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl,
sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl,
3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl,
2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl,
2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,2-dimethylbutyl,
1,3-dimethylbutyl, 2,3-dimethylbutyl, 1,1-dimethylbutyl,
2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl,
1,2,2-trimethylpropyl, 1-ethylbutyl, 2-ethylbutyl,
1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl,
2-ethylpentyl, 1-propylbutyl, n-octyl, 2-ethylhexyl,
2-propylheptyl, nonyl, decyl.
The expression "alkyl" also encompasses substituted alkyl groups
which can generally bear 1, 2, 3, 4 or 5 substituents, preferably
1, 2 or 3 substituents and particularly preferably 1 substituent,
selected from among the groups cycloalkyl, aryl, hetaryl, halogen,
NE.sup.1E.sup.2, NE.sup.1E.sup.2E.sup.3+, COOH, carboxylate,
--SO.sub.3H and sulfonate, where E.sup.1, E.sup.2 and E.sup.3 are
identical or different radicals selected from among hydrogen,
alkyl, cycloalkyl and aryl.
For the purposes of the present invention, the expression
"alkylene" refers to straight-chain or branched alkanediyl groups
having from 1 to 4 carbon atoms.
For the purposes of the present invention, the expression
"cycloalkyl" encompasses both unsubstituted and substituted
cycloalkyl groups, preferably C.sub.5-C.sub.7-cycloalkyl groups,
such as cyclopentyl, cyclohexyl or cycloheptyl, which, if they are
substituted, can generally bear 1, 2, 3, 4 or 5 substituents,
preferably 1, 2 or 3 substituents and particularly preferably 1
substituent, selected from among the groups alkyl, alkoxy and
halogen.
For the purposes of the present invention, the expression
"heterocycloalkyl" encompasses saturated, cycloaliphatic groups
which generally have from 4 to 7, preferably 5 or 6, ring atoms and
in which 1 or 2 of the ring carbons are replaced by heteroatoms
selected from among the elements oxygen, nitrogen and sulfur and
which may be substituted. If they are substituted, these
heterocycloaliphatic groups can bear 1, 2 or 3 substituents,
preferably 1 or 2 substituents, particularly preferably 1
substituent, selected from among alkyl, aryl, COOR.sup.f
(R.sup.f=hydrogen, alkyl, cycloalkyl or aryl), COO.sup.-M.sup.+and
NE.sup.1E.sup.2, preferably alkyl. Examples of such
heterocycloaliphatic groups are pyrrolidinyl, piperidinyl,
2,2,6,6-tetramethylpiperidinyl, imidazolidinyl, pyrazolidinyl,
oxazolidinyl, morpholidinyl, thiazolidinyl, isothiazolidinyl,
isoxazolidinyl, piperazinyl, tetrahydrothiophenyl,
tetrahydrofuranyl, tetrahydropyranyl, dioxanyl.
For the purposes of the present invention, the expression "aryl"
encompasses both unsubstituted and substituted aryl groups and
preferably refers to phenyl, tolyl, xylyl, mesityl, naphthyl,
fluorenyl, anthracenyl, phenanthrenyl or naphthacenyl, particularly
preferably phenyl or naphthyl. If they are substituted, these aryl
groups can generally bear 1, 2, 3, 4 or 5 substituents, preferably
1, 2 or 3 substituents and particularly preferably 1 substituent,
selected from among the groups alkyl, alkoxy, carboxyl,
carboxylate, trifluoromethyl, --SO.sub.3H, sulfonate,
NE.sup.1E.sup.2, alkylene-NE.sup.1E.sup.2, nitro, cyano and
halogen.
For the purposes of the present invention, the expression "hetaryl"
refers to unsubstituted or substituted, heterocycloaromatic groups,
preferably the groups pyridyl, quinolinyl, acridinyl, pyridazinyl,
pyrimidinyl, pyrazinyl, and also the subgroup of "pyrrole groups".
If they are substituted, these heterocycloaromatic groups can
generally bear 1, 2 or 3 substituents selected from among the
groups alkyl, alkoxy, carboxyl, carboxylate, --SO.sub.3H,
sulfonate, NE.sup.1E.sup.2, alkylene-NE.sup.1E.sup.2,
trifluoromethyl or halogen.
For the purposes of the present invention, the expression "pyrrole
group" refers to a series of unsubstituted or substituted,
heterocycloaromatic groups which are derived structurally from the
pyrrole skeleton and have a pyrrolic nitrogen atom in the
heterocycle which can be linked covalently to other atoms, for
example a pnicogen atom. The expression "pyrrole group" thus
encompasses the unsubstituted or substituted groups pyrrolyl,
imidazolyl, pyrazolyl, indolyl, purinyl, indazolyl, benzotriazolyl,
1,2,3-triazolyl, 1,3,4-triazolyl and carbazolyl, which, if they are
substituted, can generally bear 1, 2 or 3 substituents, preferably
1 or 2 substituents, particularly preferably 1 substituent,
selected from among the groups alkyl, alkoxy, acyl, carboxyl,
carboxylate, --SO.sub.3H, sulfonate, NE.sup.1E.sup.2,
alkylene-NE.sup.1E.sup.2, trifluoromethyl and halogen. A preferred
substituted indolyl group is the 3-methylindolyl group.
Accordingly, the expression "bispyrrole group" encompasses, for the
purposes of the present invention, divalent groups of the formula
Py-I-Py, which contain two pyrrole groups bound via a direct
chemical bond or a link comprising alkylene, oxa, thio, imino,
silyl or alkylimino groups, for example the bisindole diyl group of
the formula
##STR00001## as an example of a bispyrrole group containing two
directly linked pyrrole groups, in this case indolyl, or the
bispyrrole diylmethane group of the formula
##STR00002## as an example of a bispyrrole group containing two
pyrrole groups, in this case pyrrolyl, linked via a methylene
group. Like the pyrrole groups, the bispyrrole groups can also be
unsubstituted or substituted and, if they are substituted,
generally bear 1, 2 or 3 substitutents, preferably 1 or 2
substituents, in particular 1 substituent, selected from among
alkyl, alkoxy, carboxyl, carboxylate, --SO.sub.3H, sulfonate,
NE.sup.1E.sup.2, alkylene-NE.sup.1E.sup.2, trifluoromethyl and
halogen per pyrrole group unit. In these indications of the number
of possible substituents, the link between the pyrrole group units
via a direct chemical bond or via the link comprising the
abovementioned groups is not regarded as substitution.
For the purposes of the present invention, carboxylate and
sulfonate are preferably derivatives of a carboxylic acid function
or a sulfonic acid function, in particular a metal carboxylate or
sulfonate, a carboxylic ester or sulfonic ester function or a
carboxamide or sulfonamide function. Such functions include, for
example, the esters with C.sub.1-C.sub.4-alkanols, such as
methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol
and tert-butanol, and also primary amides and their N-alkyl and
N,N-dialkyl derivatives.
What has been said above with regard to the expressions "alkyl",
"cycloalkyl", "aryl", "heterocycloalkyl" and "hetaryl" applies
analogously to the expressions "alkoxy", "cycloalkoxy", "aryloxy",
"heterocycloalkoxy" and "hetaryloxy".
For the purposes of the present invention, the expression "acyl"
refers to alkanoyl or aroyl groups which generally have from 2 to
11, preferably from 2 to 8 carbon atoms, for example the acetyl,
propanoyl, butanoyl, pentanoyl, hexanoyl, heptanoyl,
2-ethylhexanoyl, 2-propylheptanoyl, benzoyl or naphthoyl group.
The radicals E.sup.1 to E.sup.12 are selected independently from
among hydrogen, alkyl, cycloalkyl and aryl. The groups
NE.sup.1E.sup.2, NE.sup.4E.sup.5, NE.sup.7E.sup.8 and
NE.sup.10E.sup.11 are preferably N,N-dimethylamino,
N,N-diethylamino, N,N-dipropylamino, N,N-diisopropylamino,
N,N-di-n-butylamino, N,N-di-t-butylamino, N,N-dicyclohexylamino or
N,N-diphenylamino.
Halogen is fluorine, chlorine, bromine or iodine, preferably
fluorine, chlorine or bromine.
M.sup.+is a cation equivalent, i.e. a monovalent cation or the part
of a polyvalent cation corresponding to a single positive charge.
The cation M.sup.+serves merely as counterion to neutralize
negatively charged substituent groups such as the COO.sup.--or
sulfonate group and can in principle be selected freely. Preference
is therefore given to using alkali metal ions, in particular
Na.sup.+, K.sup.+, Li.sup.+ions, or onium ions such as ammonium,
monoalkylammonium, dialkylammonium, trialkylammonium,
tetraalkylammonium, phosphonium, tetraalkylphosphonium or
tetraarylphosphonium ions.
An analogous situation applies to the anion equivalent X.sup.-,
which serves merely as counterion of positively charged substituent
groups such as ammonium groups and can be selected freely from
among monovalent anions and the parts of a polyvalent anion
corresponding to a single negative charge. Suitable anions are, for
example, halide ions X.sup.-, such as chloride and bromide.
Preferred anions are sulfate and sulfonate, e.g. SO.sub.4.sup.2-,
tosylate, trifluoromethanesulfonate and methylsulfonate.
x and y are each an integer from 1 to 240, preferably an integer
from 3 to 120.
Fused ring systems can be aromatic, hydroaromatic and cyclic
compounds joined by fusion. Fused ring systems comprise two, three
or more rings. Depending on the way the rings are linked, a
distinction is made in the case of fused ring systems between
ortho-fusion, i.e. each ring shares an edge or two atoms with each
adjacent ring, and peri-fusion in which one carbon atom belongs to
more than two rings. Among fused ring systems, preference is given
to ortho-fused ring systems.
The phosphoramidite compound used in the process of the invention
is preferably selected from among compounds of the formulae I and
II
##STR00003## where R.sup.1 and R.sup.5 are each, independently of
one another, pyrrole groups bound via the nitrogen atom to the
phosphorus atom, R.sup.2, R.sup.3 and R.sup.4 are each,
independently of one another, alkyl, cycloalkyl, heterocycloalkyl,
aryl or hetaryl, or R.sup.1 together with R.sup.2 and/or R.sup.4
together with R.sup.5 forms a divalent group containing at least
one pyrrole group bound via the pyrrolic nitrogen atom to the
phosphorus atom, Y is a divalent bridging group having from 2 to 20
bridge atoms between the flanking bonds, X.sup.1, X.sup.2, X.sup.3
and X.sup.4 are selected independently from among O, S,
SiR.sup..alpha.R.sup..beta.and NR.sup..gamma., where R.sup..alpha.,
R.sup..beta.and R.sup..gamma.are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, and a, b, c and d are each, independently of one another,
0 or 1.
The radicals R.sup.2, R.sup.3 and R.sup.4 in the formulae (I) and
(II) can be, independently of one another, alkyl, cycloalkyl,
heterocycloalkyl, aryl or hetaryl, where the alkyl radicals may
have 1, 2, 3, 4 or 5 substituents selected from among cycloalkyl,
heterocycloalkyl, aryl, hetaryl, alkoxy, cycloalkoxy,
heterocycloalkoxy, aryloxy, hetaryloxy, hydroxy, thiol,
polyalkylene oxide, polyalkylenimine, COOH, carboxylate, SO.sub.3H,
sulfonate, NE.sup.7E.sup.8, NE.sup.7E.sup.8E.sup.9+X.sup.-,
halogen, nitro, acyl and cyano, where E.sup.7, E.sup.8 and E.sup.9
are identical or different radicals selected from among hydrogen,
alkyl, cycloalkyl and aryl and X.sup.-is an anion equivalent, and
the cycloalkyl, heterocycloalkyl, aryl and hetaryl radicals
R.sup.2, R.sup.3 and R.sup.4 may each have 1, 2, 3, 4 or 5
substituents selected from among alkyl and the substituents
mentioned above for the alkyl radicals R.sup.2, R.sup.3 and
R.sup.4.
The substituents R.sup.2, R.sup.3 and/or R.sup.4 are advantageously
also pyrrole groups bound via the pyrrolic nitrogen atom to the
phosphorus atom.
The phosphoramidite compounds used in the process of the invention
are particularly preferably selected from among chelating
phosphoramidites. Particularly preferred chelating phosphoramidites
are the phosphoramidite compounds of the formula II.1
##STR00004## where R.sup.1, R.sup.2, R.sup.4, R.sup.5, Y, b and c
are as defined above.
In a first preferred embodiment, the substituents R.sup.1, R.sup.2,
R.sup.4 and R.sup.5 are pyrrole groups bound via the pyrrolic
nitrogen atom to the phosphorus atom, with R.sup.1 not being bound
to R.sup.2 and R.sup.4 not being bound to R.sup.5. The meaning of
the term pyrrole group here corresponds to the definition given
above.
Preference is given to chelating phosphorus compounds in which the
radicals R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are selected
independently from among groups of the formulae III.a to III.k
##STR00005## ##STR00006## where alk is a C.sub.1-C.sub.12-alkyl
group and R.sup.a, R.sup.b, R.sup.c and R.sup.d are each,
independently of one another, hydrogen, C.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkoxy, acyl, halogen,
C.sub.1-C.sub.4-alkoxycarbonyl or carboxyl.
For the purposes of illustration, some advantageous pyrrole groups
are listed below:
##STR00007## ##STR00008##
A particularly advantageous group is the 3-methylindolyl group
(skatolyl group) of the formula III.f1. Hydroformylation catalysts
based on ligands having one or more 3-methylindolyl group(s) bound
to the phosphorus atom have a particularly high stability and thus
particularly long catalyst operating lives even without
stabilization by a base.
In a further advantageous embodiment of the present invention, the
substituent R.sup.1 together with the substituent R.sup.2 and/or
the substituent R.sup.4 together with the substituent R.sup.5 in
the formulae I, II and II.1 can form a divalent group comprising a
pyrrole group bound via the pyrrolic nitrogen atom to the
phosphorus atom and having the formula Py-I--W, where Py is a
pyrrole group, I is a chemical bond or O, S,
SiR.sup..pi.R.sup..chi.,NR.sup..omega.or optionally substituted
C.sub.1-C.sub.10-alkylene, preferably CR.sup..lamda.R.sup..mu., W
is cycloalkyloxy or cycloalkylamino, aryloxy or arylamino,
hetaryloxy or hetarylamino and R.sup..pi., R.sup..chi.,
R.sup..omega., R.sup..lamda.and R.sup..mu.are each, independently
of one another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl
or hetaryl, where the terms used here have the meanings indicated
above.
Preferred divalent groups of the formula Py-I--W are, for
example:
##STR00009##
Preference is given to phosphoramidites in which the substituent
R.sup.1 together with the substituent R.sup.2 and/or the
substituent R.sup.4 together with the substituent R.sup.5 forms a
bispyrrole group of the formula
##STR00010## where I is a chemical bond or O, S,
SiR.sup..pi.R.sup..chi., NR.sup..omega.or optionally substituted
C.sub.1-C.sub.10-alkylene, preferably CR.sup..lamda.R.sup..mu.,
where R.sup..pi., R.sup..chi., R.sup..omega., R.sup..lamda.and
R.sup..mu.are each, independently of one another, hydrogen, alkyl,
cycloalkyl, heterocycloalkyl, aryl or hetaryl, R.sup.15, R.sup.15',
R.sup.16, R.sup.16', R.sup.17, R.sup.17', R.sup.18 and R.sup.18'are
each, independently of one another, hydrogen, alkyl, cycloalkyl,
heterocycloalkyl, aryl, hetaryl, W'COOR.sup.f, W'COO.sup.-M.sup.+,
W'(SO.sub.3)R.sup.f, W'(SO.sub.3).sup.-M.sup.+,
W'PO.sub.3(R.sup.f)(R.sup.g), W'(PO.sub.3).sup.2-(M.sup.+).sub.2,
W'NE.sup.10E.sup.11, W'(NE.sup.10E.sup.11E.sup.12).sup.+X.sup.-,
W'OR.sup.f, W'SR.sup.f, (CHR.sup.gCH.sub.2O).sub.xR.sup.f,
(CH.sub.2NE.sup.10).sub.x R.sup.f,
(CH.sub.2CH.sub.2NE.sup.10).sub.xR.sup.f, halogen, trifluoromethyl,
nitro, acyl or cyano, where W' is a single bond, a heteroatom, a
heteroatom-containing group or a divalent bridging group having
from 1 to 20 bridge atoms, R.sup.f, E.sup.10, E.sup.11, E.sup.12
are identical or different radicals selected from among hydrogen,
alkyl, cycloalkyl and aryl, R.sup.g is hydrogen, methyl or ethyl,
M.sup.+is a cation equivalent, X.sup.-is an anion equivalent and x
is an integer from 1 to 240, where two adjacent radicals R.sup.15
and R.sup.16 and/or R.sup.15'and R.sup.16'together with the carbon
atoms of the pyrrole ring to which they are bound may also form a
fused ring system having 1, 2 or 3 further rings.
I is preferably a chemical bond or a C.sub.1-C.sub.4-alkylene
group, particularly preferably a methylene group.
For the purposes of illustration, a few advantageous "bispyrrolyl
groups" are listed below:
##STR00011##
In a preferred embodiment, the bridging group Y in the formulae
(I), (II) and (II.1) is selected from among groups of the formulae
IV.a to IV.u
##STR00012## ##STR00013## ##STR00014## where R.sup.I, R.sup.I',
R.sup.II, R.sup.II', R.sup.III, R.sup.III', R.sup.IV, R.sup.IV',
R.sup.V, R.sup.VI, R.sup.VII, R.sup.VIII, R.sup.IX, R.sup.X,
R.sup.XI and R.sup.XII are each, independently of one another,
hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl,
hydroxy, thiol, polyalkylene oxide, polyalkylenimine, alkoxy,
halogen, SO.sub.3H, sulfonate, NE.sup.1E.sup.2,
alkylene-NE.sup.1E.sup.2, nitro, alkoxycarbonyl, carboxyl, acyl or
cyano, where E.sup.1 and E.sup.2 are identical or different
radicals selected from among hydrogen, alkyl, cycloalkyl and aryl,
Z is O, S, NR.sup..delta.or SiR.sup..delta.R.sup..epsilon., where
R.sup..delta.and R.sup..epsilon.are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, or Z is a C.sub.1-C.sub.4-alkylene bridge which may have a
double bond and/or bear an alkyl, cycloalkyl, heterocycloalkyl,
aryl or hetaryl substituent, or Z is a C.sub.2-C.sub.4-alkylene
bridge which is interrupted by O, S or NR.sup..delta.or
SiR.sup..delta.R.sup..epsilon., where, in the groups of the
formulae IV.a and IV.b, two adjacent radicals R.sup.I to R.sup.VI
together with the carbon atoms of the benzene ring to which they
are bound may also form a fused ring system having 1, 2 or 3
further rings, where, in the groups of the formulae IV.h to IV.n,
two geminal radicals R.sup.I, R.sup.I'; R.sup.II, R.sup.II';
R.sup.III, R.sup.III'and/or R.sup.IV, R.sup.IV'may also represent
oxo or a ketal thereof, A.sup.1 and A.sup.2 are each, independently
of one another, O, S, SiR.sup..phi.R.sup..gamma., NR.sup..eta.or
CR.sup.R.sup..kappa., where R.sup..phi., R.sup..gamma.,
R.sup..eta., R.sup.and R.sup..kappa.are each, independently of one
another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or
hetaryl, A.sup.3 and A.sup.4 are each, independently of one
another, SiR.sup..phi., N or CR.sup., D is a divalent bridging
group of the formula
##STR00015## where R.sup.9, R.sup.9', R.sup.10 and R.sup.10'are
each, independently of one another, hydrogen, alkyl, cycloalkyl,
aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano,
where R.sup.9'together with R.sup.10'can also represent the second
bond of a double bond between the two carbon atoms to which
R.sup.9'and R.sup.10'are bound, and/or R.sup.9 and R.sup.10
together with the carbon atoms to which they are bound may also
form a 4- to 8-membered carbocycle or heterocycle which may
additionally be fused with one, two or three cycloalkyl,
heterocycloalkyl, aryl or hetaryl groups, where the heterocycle
and, if present, the fused-on groups may each bear, independently
of one another, one, two, three or four substituents selected from
among alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl,
COOR.sup.f, COO.sup.-M.sup.+, SO.sub.3R.sup.f,
SO.sup.-.sub.3M.sup.+, NE.sup.4E.sup.5, alkylene-NE.sup.4E.sup.5,
NE.sup.4E.sup.5E.sup.6+X.sup.-,
alkylene-NE.sup.4E.sup.5E.sup.6+X.sup.-, OR.sup.f, SR.sup.f,
(CHR.sup.eCH.sub.2O).sub.yR.sup.f,
(CH.sub.2N(E.sup.4)).sub.yR.sup.f,
(CH.sub.2CH.sub.2N(E.sup.4)).sub.yR.sup.f, halogen,
trifluoromethyl, nitro, acyl and cyano, where R.sup.f, E.sup.4,
E.sup.5 and E.sup.6 are identical or different radicals selected
from among hydrogen, alkyl, cycloalkyl and aryl, R.sup.e is
hydrogen, methyl or ethyl, M.sup.+is a cation, X.sup.-is an anion
and y is an integer from 1 to 240.
Preference is given to the bridging group Y being a group of the
formula IV.a in which the groups A.sup.1 and A.sup.2 are selected
from among the groups O, S and CR.sup.iR.sup.k, in particular from
among O, S, the methylene group (R.sup.i=R.sup.k=H), the
dimethylmethylene group (R.sup.i=R.sup.k=CH.sub.3), the
diethylmethylene group (R.sup.i=R.sup.k=C.sub.2H.sub.5), the
di-n-propylmethylene group (R.sup.i=R.sup.k=n-propyl) or the
di-n-butylmethylene group (R.sup.d=R.sup.e=n-butyl). Particular
preference is given to bridging groups Y in which A.sup.1 is
different from A.sup.2, with A.sup.1 preferably being a
CR.sup.iR.sup.k group and A.sup.2 preferably being an O or S group,
particularly preferably an oxa group O.
Preference is given to the bridging group Y being a group of the
formula IV.b in which D is a divalent bridging group selected from
among the groups
##STR00016## where R.sup.9, R.sup.9', R.sup.10 and R.sup.10'are
each, independently of one another, hydrogen, alkyl, cycloalkyl,
aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or
are joined to one another to form a C.sub.3-C.sub.4-alkylene group
and R.sup.11, R.sup.12, R.sup.13 and R.sup.14 can each be,
independently of one another, hydrogen, alkyl, cycloalkyl, aryl,
halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy,
SO.sub.3H, sulfonate, NE.sup.1E.sup.2,
alkylene-NE.sup.1E.sup.2E.sup.3+X.sup.-, aryl or nitro. Preference
is given to the groups R.sup.9, R.sup.9', R.sup.10 and
R.sup.10'each being hydrogen, C.sub.1-C.sub.10-alkyl or carboxylate
and the groups R.sup.11, R.sup.12, R.sup.13 and R.sup.14 each being
hydrogen, C.sub.1-C.sub.10-alkyl, halogen, in particular fluorine,
chlorine or bromine, trifluoromethyl, C.sub.1-C.sub.4-alkoxy,
carboxylate, sulfonate or C.sub.1-C.sub.8-aryl. R.sup.9, R.sup.9',
R.sup.10, R.sup.10', R.sup.11, R.sup.12, R.sup.13 and R.sup.14 are
particularly preferably each hydrogen. For use in an aqueous
reaction medium, preference is given to chelating pnicogen
compounds in which 1, 2 or 3, preferably 1 or 2, in particular 1,
of the groups R.sup.11, R.sup.12, R.sup.13 and/or R.sup.14 are a
COO.sup.-M.sup.+, SO.sub.3.sup.-M.sup.+or
(NE.sup.1E.sup.2E.sup.3).sup.+X.sup.-group, where M.sup.+and
X.sup.-are as defined above.
Particularly preferred bridging groups D are the ethylene group
##STR00017## and the 1,2-phenylene group
##STR00018##
In the bridging groups Y of the formulae IV.a and IV.b, the
substituents R.sup.I, R.sup.II, R.sup.III, R.sup.IV, R.sup.V and
R.sup.VI are preferably selected from among hydrogen, alkyl,
alkoxy, cycloalkyl, heterocycloalkyl, aryl and hetaryl. In a first
preferred embodiment, R.sup.I, R.sup.II, R.sup.III, R.sup.IV,
R.sup.V and R.sup.VI are each hydrogen. In a further preferred
embodiment, R.sup.I and R.sup.V are each, independently of one
another, C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.I
and R.sup.VI are preferably selected from among methyl, ethyl,
isopropyl, tert-butyl and methoxy. In these compounds, R.sup.II,
R.sup.III, R.sup.IV and R.sup.V are preferably each hydrogen. In a
further preferred embodiment, R.sup.II and R.sup.V are each,
independently of one another, C.sub.1-C.sub.4-alkyl or
C.sub.1-C.sub.4-alkoxy. R.sup.II and R.sup.V are preferably
selected from among methyl, ethyl, isopropyl and tert-butyl. In
these compounds, R.sup.I, R.sup.III, R.sup.IV and R.sup.VI are
preferably each hydrogen.
When two adjacent radicals selected from among R.sup.I, R.sup.II,
R.sup.III, R.sup.IV, R.sup.V and R.sup.VI in the bridging groups Y
of the formulae IV.a and IV.b form a fused-on ring system, this is
preferably a benzene ring or naphthalene unit. Fused-on benzene
rings are preferably unsubstituted or have 1, 2 or 3, in particular
1 or 2, substituents selected from among alkyl, alkoxy, halogen,
SO.sub.3H, sulfonate, NE.sup.1E.sup.2, alkylene-NE.sup.1E.sup.2,
trifluoromethyl, nitro, COOR.sup.f, alkoxycarbonyl, acyl and cyano.
Fused-on naphthalene units are preferably unsubstituted or have a
total of 1, 2 or 3, in particular 1 or 2, of the substituents
mentioned above in the case of the fused-on benzene rings in the
ring which is not fused on and/or in the fused-on ring.
Preference is given to Y being a group of the formula IV.c in which
R.sup.IV and R.sup.V are each, independently of one another,
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.IV and
R.sup.V are preferably selected from among methyl, ethyl,
isopropyl, tert-butyl and methoxy. In these compounds R.sup.I,
R.sup.II, R.sup.III, R.sup.VI, R.sup.VII and R.sup.VIII are
preferably each hydrogen.
Preference is also given to Y being a group of the formula IV.c in
which R.sup.I and R.sup.VIII are each, independently of one
another, C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy.
R.sup.Iand R.sup.VIII are particularly preferably each tert-butyl.
In these compounds, R.sup.II, R.sup.III, R.sup.IV, R.sup.V,
R.sup.VI, R.sup.VII are particularly preferably each hydrogen.
Preference is also given to R.sup.III and R.sup.VI in these
compounds each being, independently of one another,
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.III and
R.sup.VI are particularly preferably selected independently from
among methyl, ethyl, isopropyl, tert-butyl and methoxy.
Preference is also given to Y being a group of the formula IV.c in
which R.sup.II and R.sup.VII are each hydrogen. In these compounds
R.sup.I, R.sup.III, R.sup.IV, R.sup.V, R.sup.VI and R.sup.VIII are
preferably each, independently of one another,
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.I,
R.sup.III, R.sup.IV, R.sup.V, R.sup.VI and R.sup.VIII are
particularly preferably selected independently from among methyl,
ethyl, isopropyl, tert-butyl and methoxy.
Furthermore, preference is given to Y being a group of the formula
IV.d in which Z is a C.sub.1-C.sub.4-alkylene group, in particular
methylene. In these compounds, R.sup.IV and R.sup.V are preferably
each, independently of one another, C.sub.1-C.sub.4-alkyl or
C.sub.1-C.sub.4-alkoxy. R.sup.IV and R.sup.V are particularly
preferably selected independently from among methyl, ethyl,
isopropyl, tert-butyl and methoxy. The radicals R.sup.I, R.sup.II,
R.sup.III, R.sup.VI, R.sup.VII and R.sup.VIII are preferably each
hydrogen.
Preference is also given to Y being a group of the formula IV.d in
which Z is a C.sub.1-C.sub.4-alkylene bridge bearing at least one
alkyl, cycloalkyl or aryl radical. Z is particularly preferably a
methylene bridge bearing two C.sub.1-C.sub.4-alkyl radicals, in
particular two methyl radicals. In these compounds, the radicals
R.sup.I and R.sup.VIII are preferably each, independently of one
another, C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.I
and R.sup.VIII are particularly preferably selected independently
from among methyl, ethyl, isopropyl, tert-butyl and methoxy.
Furthermore, preference is given to Y being a group of the formula
IV.e in which R.sup.I and R.sup.XII are each, independently of one
another, C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. In
particular, R.sup.I and R.sup.XII are selected independently from
among methyl, ethyl, isopropyl, tert-butyl, methoxy and
alkoxycarbonyl, preferably methoxycarbonyl. In these compounds, the
radicals R.sup.II to R.sup.XI are particularly preferably each
hydrogen.
Preference is also given to Y being a group of the formula IV.f in
which R.sup.I and R.sup.XII are each, independently of one another,
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. In particular,
R.sup.I and R.sup.XII are selected independently from among methyl,
ethyl, isopropyl, tert-butyl and methoxy. In these compounds, the
radicals R.sup.II to R.sup.XI are particularly preferably each
hydrogen.
Furthermore, preference is given to Y being a group of the formula
IV.g in which Z is a C.sub.1-C.sub.4-alkylene group bearing at
least one alkyl, cycloalkyl or aryl substituent. Z is particularly
preferably a methylene group bearing two C.sub.1-C.sub.4-alkyl
radicals, especially two methyl radicals. In these compounds, the
radicals R.sup.I and R.sup.VIII are particularly preferably each,
independently of one another, C.sub.1-C.sub.4-alkyl or
C.sub.1-C.sub.4-alkoxy. In particular, R.sup.Iand R.sup.VIII are
selected independently from among methyl, ethyl, isopropyl,
tert-butyl and methoxy. The radicals R.sup.II, R.sup.III, R.sup.IV,
R.sup.V, R.sup.VI and R.sup.VII are preferably each hydrogen.
Preference is also given to Y being a group of the formula IV.h in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III and
R.sup.III'are each hydrogen.
Preference is also given to Y being a group of the formula IV.h in
which R.sup.II and R.sup.II' together represent an oxo group or a
ketal thereof and the other radicals are each hydrogen.
Preference is also given to Y being a group of the formula IV.i in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III and
R.sup.III'are each hydrogen.
Preference is also given to Y being a group of the formula IV.i in
which R.sup.II and R.sup.II'together represent an oxo group or a
ketal thereof and the other radicals are each hydrogen.
Preference is also given to Y being a group of the formula IV.k in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III,
R.sup.III', R.sup.IV and R.sup.IV'are each hydrogen.
Preference is also given to Y being a group of the formula IV.l in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III,
R.sup.III', R.sup.IV and R.sup.IV'are each hydrogen.
Preference is also given to Y being a group of the formula IV.m in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III,
R.sup.III', R.sup.IV and R.sup.IV'are each hydrogen.
Preference is also given to Y being a group of the formula IV.n in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III,
R.sup.III', R.sup.IV and R.sup.IV'are each hydrogen.
Preference is also given to Y being a group of the formula IV.o in
which R.sup.I, R.sup.I', R.sup.II, R.sup.II', R.sup.III,
R.sup.III', R.sup.IV and R.sup.IV'are each hydrogen.
Preference is also given to Y being a group of the formula IV.o in
which one of the radicals R.sup.I to R.sup.IV is
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. Particular
preference is then given to at least one of the radicals R.sup.I to
R.sup.IV being methyl, ethyl, isopropyl, tert-butyl or methoxy.
Preference is also given to Y being a group of the formula IV.p in
which R.sup.I, R.sup.II, R.sup.III and R.sup.IV are each
hydrogen.
Preference is also given to Y being a group of the formula IV.p in
which one of the radicals R.sup.I, R.sup.II, R.sup.III or R.sup.IV
is C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. Particular
preference is then given to one of the radicals R.sup.I to R.sup.IV
being methyl, ethyl, tert-butyl or methoxy.
Preference is also given to Y being a group of the formula IV.q in
which R.sup.I and R.sup.VI are each, independently of one another,
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.I and
R.sup.VI are particularly preferably selected independently from
among methyl, ethyl, isopropyl, tert-butyl and methoxy. In these
compounds, R.sup.II, R.sup.III, R.sup.IV and R.sup.V are
particularly preferably each hydrogen. Preference is also given to
R.sup.I, R.sup.III, R.sup.IV and R.sup.VI in the compounds IV.q
each being, independently of one another, C.sub.1-C.sub.4-alkyl or
C.sub.1-C.sub.4-alkoxy. Particular preference is then given to
R.sup.I, R.sup.III, R.sup.IV and R.sup.VI being selected
independently from among methyl, ethyl, isopropyl, tert-butyl and
methoxy.
Preference is also given to Y being a group of the formula IV.r in
which R.sup.I and R.sup.VI are each, independently of one another,
C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy. R.sup.I and
R.sup.VI are particularly preferably selected independently from
among methyl, ethyl, isopropyl, tert-butyl and methoxy. In these
compounds, R.sup.II, R.sup.III, R.sup.IV and R.sup.V are
particularly preferably each hydrogen. Preference is also given to
R.sup.III and R.sup.IV in these compounds each being, independently
of one another, C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkoxy.
Particular preference is then given to R.sup.III and R.sup.IV being
selected independently from among methyl, ethyl, isopropyl,
tert-butyl and methoxy.
Preference is also given to Y being a group of the formula IV.s,
IV.t or IV.u in which Z is CH.sub.2, C.sub.2H.sub.2 or
C.sub.2H.sub.4.
In the compounds of the formulae IV.s, IV.t and IV.u, the indicated
bonds to the bridged groups can equally well be in the endo and exo
positions.
The catalysts used according to the invention can further comprise
at least one additional ligand which is preferably selected from
among halides, amines, carboxylates, acetylacetonate,
arylsulfonates and alkylsulfonates, hydride, CO, olefins, dienes,
cycloolefins, nitriles, N-containing heterocycles, aromatics and
heteroaromatics, ethers, PF.sub.3, phospholes, phosphabenzenes,
monodentate, bidentate and polydentate phosphine, phosphinite,
phosphonite, phosphite ligands and mixtures thereof.
In general, the catalysts or catalyst precursors used in each case
are converted under hydroformylation conditions into catalytically
active species of the formula H.sub.tM.sub.u(CO).sub.vL.sub.w,
where M is a metal of transition group VIII, L is a phosphoramidite
compound and t, u, v, w are integers which depend on the valence
and type of the metal and on the number of coordination sites
occupied by the ligand L. It is preferred that v and w each have,
independently of one another, a value of at least 1, e.g. 1, 2 or
3. The sum of v and w is preferably from 1 to 5. If desired, the
complexes may further comprise at least one of the above-described
additional ligands.
In a preferred embodiment, the hydroformylation catalysts are
prepared in situ in the reactor used for the hydroformylation
reaction. However, the catalysts used according to the invention
can, if desired, also be prepared separately and isolated by
customary methods. For the in-situ preparation of the catalysts
used according to the invention, it is possible, for example, to
react at least one phosphoramidite compound, a compound or a
complex of a metal of transition group VIII, if appropriate at
least one further additional ligand and, if appropriate, an
activating agent in an inert solvent under the hydroformylation
conditions.
Suitable rhodium compounds or complexes are, for example,
rhodium(II) and rhodium(III) salts such as rhodium(II) chloride,
rhodium(III) nitrate, rhodium(III) sulfate, potassium rhodium
sulfate, rhodium(II) or rhodium(III) carboxylate, rhodium(II) and
rhodium(III) acetate, rhodium(II) and rhodium(III) ethylhexanoate,
rhodium(III) oxide, salts of rhodic(III) acid, trisammonium
hexachlororhodate(III), etc. Also suitable are rhodium complexes
such as dicarbonylrhodium acetylacetonate,
acetylacetonato-bisethylenerhodium(I), etc. Preference is given to
using dicarbonylrhodium acetylacetonate or rhodium acetate.
Likewise suitable are ruthenium salts or compounds. Suitable
ruthenium salts are, for example, ruthenium(III) chloride,
ruthenium(IV), ruthenium(VI) or ruthenium(VIII) oxide, alkali metal
salts of ruthenium oxo acids such as K.sub.2RuO.sub.4 or KRuO.sub.4
or complexes such as RuHCl(CO)(PPh.sub.3).sub.3. It is also
possible to use the metal carbonyls of ruthenium, for example
dodecacarbonyltriruthenium or octadecacarbonylhexaruthenium, or
mixed forms in which CO is partly replaced by ligands of the
formula PR.sub.3, e.g. Ru(CO).sub.3(PPh.sub.3).sub.2, in the
process of the invention.
Suitable cobalt compounds are, for example, cobalt(II) chloride,
cobalt(II) sulfate, cobalt(II) carbonate, cobalt(II) nitrate, their
amine or hydrate complexes, cobalt carboxylates, such as cobalt
acetate, cobalt ethylhexanoate, cobalt naphthanoate, and also the
cobalt caproate complex. Here too, the carbonyl complexes of cobalt
such as octacarbonyl dicobalt, dodecacarbonyl tetracobalt and
hexadecacarbonyl hexacobalt can be used.
The abovementioned and further suitable compounds of cobalt,
rhodium, ruthenium and iridium are known in principle and are
adequately described in the literature or can be prepared by a
person skilled in the art by methods analogous to those for the
known compounds.
Suitable activating agents are, for example, Bronsted acids, Lewis
acids, e.g. BF.sub.3, AlCl.sub.3, ZnCl.sub.2, SnCl.sub.2 and Lewis
bases.
Suitable starting olefins for the process of the invention are in
principle all compounds which contain one or more ethylenically
unsaturated double bonds. These include olefins having terminal or
internal double bonds, straight-chain or branched olefins, cyclic
olefins and also olefins which bear substituents which are
essentially inert under the hydroformylation conditions. Preference
is given to starting olefins comprising olefins having from 4 to
12, particularly preferably from 4 to 6, carbon atoms. The olefins
used for the hydroformylation are preferably selected from among
linear (straight-chain) olefins and olefin mixtures comprising at
least one linear olefin. The process of the invention makes it
possible to hydroformylate, in particular, linear .alpha.-olefins,
linear internal olefins and mixtures of linear .alpha.-olefins and
linear internal olefins.
.alpha.-Olefins preferred as substrates for the hydroformylation
process of the invention are C.sub.4-C.sub.20-.alpha.-olefins, e.g.
1-butene, isobutene, 1-pentene, 2-methyl-1-butene, 1-hexene,
1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene,
allyl alcohols, etc.
Preference is given to linear .alpha.-olefins and olefin mixtures
comprising at least one linear .alpha.-olefin.
The unsaturated compound used for the hydroformylation is
preferably selected from among internal linear olefins and olefin
mixtures comprising at least one internal linear olefin. Preferred
linear internal olefins are C.sub.4-C.sub.20-olefins, such as
2-butene, 2-pentene, 2-hexene, 3-hexene, 2-heptene, 3-heptene,
2-octene, 3-octene, 4-octene, etc., and mixtures thereof.
Preferred branched, internal olefins are C.sub.4-C.sub.20-olefins
such as 2-methyl-2-butene, 2-methyl-2-pentene, 3-methyl-2-pentene,
branched, internal heptene mixtures, branched, internal octene
mixtures, branched, internal nonene mixtures, branched, internal
decene mixtures, branched, internal undecene mixtures, branched,
internal dodecene mixtures, etc.
Further olefins suitable for the hydroformylation process are
C.sub.5-C.sub.8-cycloalkenes, such as cyclopentene, cyclohexene,
cycloheptene, cyclooctene and derivatives thereof, e.g.
their C.sub.1-C.sub.20-alkyl derivatives having from 1 to 5 alkyl
substituents. Other olefins suitable for the hydroformylation
process are vinylaromatics such as styrene, .alpha.-methylstyrene,
4-isobutylstyrene, etc. Olefins suitable for the hydroformylation
process additionally include .alpha.,.beta.-ethylenically
unsaturated monocarboxylic and/or dicarboxylic acids, their esters,
semiesters and amides, e.g. acrylic acid, methacrylic acid, maleic
acid, fumaric acid, crotonic acid, itaconic acid, methyl
3-pentenoate, methyl 4-pentenoate, methyl oleate, methyl acrylate
and methyl methacrylate. Further olefins suitable for the
hydroformylation process are unsaturated nitriles, such as
3-pentenenitrile, 4-pentenenitrile and acrylonitrile. Further
olefins suitable for the hydroformylation process are vinyl ethers,
e.g. vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether,
etc. Other olefins suitable for the hydroformylation process are
alkenols, alkenediols and alkadienols such as 2,7-octadien-1-ol.
Further olefins suitable for the hydroformylation process are
dienes or polyenes having isolated or conjugated double bonds.
These include, for example, 1,3-butadiene, 1,4-pentadiene,
1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,9-decadiene,
vinylcyclohexene, dicyclopentadiene, 1,5,9-cyclooctatriene,
homopolymers and copolymers of butadiene and also olefins having
terminal and internal double bonds, e.g. 1,4-octadiene.
The hydroformylation process of the invention is preferably carried
out using an industrially available olefin-containing hydrocarbon
mixture.
Preferred olefin mixtures which are available on an industrial
scale result from the cracking of hydrocarbons in petroleum
processing, for example by catalytic cracking such as fluid
catalytic cracking (FCC), thermal cracking or hydrocracking with
subsequent dehydrogenation. One suitable industrial olefin mixture
is a C.sub.4 fraction. C.sub.4 fractions can be obtained, for
example, by fluid catalytic cracking or steam cracking of gas oil
or by steam cracking naphtha. Depending on the composition of the
C.sub.4 fraction, a distinction is made between the total C.sub.4
fraction (raw C.sub.4 fraction), the raffinate I obtained after
1,3-butadiene has been separated off and also the raffinate II
obtained after the isobutene has been separated off. A further
suitable industrial olefin mixture is the C.sub.5 fraction
obtainable in the cracking of naphtha. Olefin-containing
hydrocarbon mixtures containing compounds having from 4 to 6 carbon
atoms which are suitable for use in step a) can also be obtained by
catalytic dehydrogenation of suitable industrially available
paraffin mixtures. Thus, for example, C.sub.4 olefin mixtures can
be produced from liquefied petroleum gas (LPG) and liquefied
natural gas (LNG). The latter comprises, in addition to the LPG
fraction, relatively large amounts of high molecular weight
hydrocarbons (light naphtha) and is thus also suitable for
preparing C.sub.5- and C.sub.6-olefin mixtures. Olefin-containing
hydrocarbon mixtures comprising monoolefins having from 4 to 6
carbon atoms can be prepared from LPG or LNG streams by
conventional methods known to those skilled in the art which, in
addition to dehydrogenation, generally comprise one or more work-up
steps. Such steps include, for example, the removal of at least
part of the saturated hydrocarbons present in the abovementioned
olefin feed mixtures. The saturated hydrocarbons can, for example,
be reused for the preparation of starting olefins by cracking
and/or dehydrogenation. However, the olefins used in the process of
the invention can also contain a proportion of saturated
hydrocarbons which are inert under the hydroformylation conditions
of the invention. The proportion of these saturated components is
generally not more than 60% by weight, preferably not more than 40%
by weight, particularly preferably not more than 20% by weight,
based on the total amount of olefins and saturated hydrocarbons
present in the hydrocarbon starting material.
A raffinate II suitable for use in the process of the invention
has, for example, the following composition: from 0.5 to 5% by
weight of isobutane, from 5 to 20% by weight of n-butane, from 20
to 40% by weight of trans-2-butene, from 10 to 20% by weight of
cis-2-butene, from 25 to 55% by weight of 1-butene, from 0.5 to 5%
by weight of isobutene and also trace gases such as 1,3-butadiene,
propene, propane, cyclopropane, propadiene, methylcyclopropane,
vinylacetylene, pentenes, pentanes, etc., in concentrations of not
more than 1% by weight in each case.
It has surprisingly been found that catalytically active fluids
based on metal complexes of phosphoramidite compounds can be
additionally stabilized by bringing them into contact with a base.
Thus, longer catalyst operating lives are achieved in the process
of the invention than in hydroformylation processes known from the
prior art which use catalysts based either on conventional
monodentate and polydentate ligands or, in particular, based on
phosphoramidite ligands. The catalytic activity is generally not
adversely affected by contacting with the base.
The invention further provides a method of stabilizing a
catalytically active fluid comprising a dissolved metal complex of
a metal of transition group VIII of the Periodic Table of the
Elements with at least one phosphoramidite compound as ligand in
the hydroformylation of ethylenically unsaturated compounds, which
comprises bringing the fluid into contact with a base.
The invention also provides for the use of bases for stabilizing a
catalytically active fluid comprising a dissolved metal complex of
a metal of transition group VIII of the Periodic Table of the
Elements with at least one phosphoramidite compound as ligand in
the hydroformylation of ethylenically unsaturated compounds.
The invention is illustrated by the following nonrestrictive
examples.
EXAMPLES
1. Preparation of the Compound (1)
28.5 g (218 mmol) of 3-methylindole (skatole) together with about
50 ml of dried toluene were placed in a reaction vessel and the
solvent was distilled off under reduced pressure to remove traces
of water by azeotropic distillation. This procedure was repeated
once more. The residue was subsequently taken up in 700 ml of dried
toluene under argon and cooled to -65.degree. C. 14.9 g (109 mmol)
of PCl.sub.3 followed by 40 g (396 mmol) of triethylamine were then
added slowly at -65.degree. C. The reaction mixture was brought to
room temperature over a period of 16 hours and then refluxed for 16
hours. 19.3 g (58 mmol) of
4,5-dihydroxy-2,7-di-tert-butyl-9,9-dimethylxanthene in 300 ml of
dried toluene were added to the reaction mixture, the mixture was
then refluxed for 16 hours and, after cooling to room temperature,
the colorless solid which had precipitated (triethylamine
hydrochloride) was filtered off with suction, the solvent was
distilled off and the residue was recrystallized twice from hot
ethanol. Drying under reduced pressure gave 36.3 g (71% of theory)
of a colorless solid.
.sup.31P-NMR (298K): .delta.=105 ppm.
##STR00019## 2. Hydroformylation of Trans-2-butene without Additive
(Comparative Example)
0.005 g of Rh(CO).sub.2(acac) and 0.181 g of the compound (1) were
dissolved in 10.17 g of xylene under a protective gas atmosphere
and the mixture was transferred to a 100 ml steel autoclave. The
autoclave was pressurized with 10 bar of synthesis gas
(CO/H.sub.2=1:2) and then heated to 90.degree. C. over a period of
one hour. The autoclave was then carefully depressurized to 7 bar
at 90.degree. C., and 10.81 g of a liquefied gas mixture (30% by
volume of trans-2-butene and 70% by volume of isobutane) were
injected via a lock by means of synthesis gas of the abovementioned
composition (p=12 bar). The pressure was then set to 16 bar (total)
by means of the synthesis gas. During the reaction time of 4 hours,
the temperature was kept at 90.degree. C. and the pressure was
maintained at 16 bar (total) by addition of CO/H.sub.2 (1:1). After
the reaction was complete, the autoclave was depressurized via a
cold trap and the contents of the autoclave and of the cold trap
were analyzed by gas chromatography in order to determine the
conversion, the yield of pentanals and the proportion of
n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00001 Conversion 32% Yield 31% Proportion of n product
93%
3. Degradation Experiment with Addition of N,N-dimethylaniline
0.005 g of Rh(CO).sub.2(acac), 0.181 g of compound (1) and 0.26 g
of N,N-dimethylaniline were dissolved in 8.12 g of Texanole.RTM.
(2,2,4-trimethyl-1,3-pentanediol monobutyrate, from Eastman) under
a protective gas atmosphere and the mixture was transferred to a 60
ml steel autoclave. The autoclave was pressurized at 25.degree. C.
with 20 bar of CO/H.sub.2 (1:1) and heated to 120.degree. C. over a
period of 60 minutes. The autoclave was then carefully
depressurized to 7 bar at 120.degree. C. and 11.23 g of a liquefied
gas mixture (2.9% by volume of isobutane; 14.6% by volume of
n-butane; 27.4% by volume of trans-2-butene; 37.4% by volume of
1-butene; 2.6% by volume of isobutene; 15.3% of cis-2-butene) were
injected via a lock by means of CO/H.sub.2 (1:1) at 12 bar. The
pressure was increased to 28 bar (total) by means of CO/H.sub.2
(1:1) and the autoclave was maintained at 120.degree. C. for 24
hours. After the end of the reaction time, the autoclave was
cooled, depressurized and a sample for .sup.31P-NMR analysis was
taken under a protective gas atmosphere to determine the degree to
which the ligand had been degraded.
Integration of the .sup.31P-NMR spectrum indicated that 18% of the
compound (1) had been degraded.
The mixture was subsequently returned to the autoclave, the
autoclave was flushed three times with nitrogen and then maintained
at 120.degree. C. and a nitrogen pressure of 3 bar for 24 hours to
simulate long-term stressing of the catalyst as occurs in prolonged
continuous operation. After the end of the reaction time, the
autoclave was cooled, depressurized and a sample for .sup.31P-NMR
analysis was taken under a protective gas atmosphere in order to
determine the degree to which the ligand had been degraded.
Integration of the .sup.31P-NMR spectrum indicated that a total of
only 42% of the compound (1) had been degraded.
4. Hydroformylation of Trans-2-butene with Addition of
N,N-dimethylaniline
0.005 g of Rh(CO).sub.2(acac), 0.181 g of the compound (1) and
0.025 g of N,N-dimethyl-aniline were dissolved in 10.17 g of xylene
under a protective gas atmosphere and the mixture was transferred
to a 100 ml steel autoclave. The autoclave was pressurized with 10
bar of CO/H.sub.2 (1:2) and was then heated to 90.degree. C. over a
period of 1 hour. The autoclave was then carefully depressurized to
7 bar at 90.degree. C. and 10.81 g of a liquefied gas mixture (30%
by volume of trans-2-butene and 70% by volume of isobutane) were
injected via a lock by means of CO/H.sub.2 (1:2) at 12 bar and the
pressure was set to 16 bar (total) by means of CO/H.sub.2 (1:2).
During the reaction time of 4 hours, the temperature was kept at
90.degree. C. and the pressure was maintained at 16 bar (total) by
means of CO/H.sub.2 (1:1). After the end of the reaction, the
autoclave was depressurized via a cold trap and the contents of the
autoclave and of the cold trap were analyzed by gas chromatography
in order to determine the conversion, the yield of pentanals and
the proportion of n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00002 Conversion 30% Yield 28% Proportion of n product
94%
Conversion, yield and proportion of n product were not reduced
significantly compared to comparative example 2 by addition of the
base.
5. Degradation Experiment with Addition of
N,N,2,4,6-pentamethylaniline
0.005 g of Rh(CO).sub.2(acac), 0.181 g of compound (1) and 0.35 g
of N,N,2,4,6-penta-methylaniline were dissolved in 8.11 g of
Texanol under a protective gas atmosphere and the mixture was
transferred to a 60 ml steel autoclave. The autoclave was
pressurized with 20 bar of CO/H.sub.2 (1:1) at 25.degree. C. and
was then heated to 120.degree. C. over a period of 60 minutes. The
autoclave was then carefully depressurized to 7 bar at 120.degree.
C. and 11.23 g of a liquefied gas mixture (2.9% by volume of
isobutane; 14.6% by volume of n-butane; 27.4% by volume of
trans-2-butene; 37.4% by volume of 1-butene; 2.6% by volume of
isobutene; 15.3% of cis-2-butene) were then injected via a lock by
means of CO/H.sub.2 (1:1) at 12 bar. The pressure was increased to
28 bar (total) by means of CO/H.sub.2 (1:1) and the autoclave was
maintained at 120.degree. C. for 24 hours.
After the end of the reaction time, the autoclave was cooled,
depressurized and a sample for .sup.31P-NMR analysis was taken
under a protective gas atmosphere to determine the degree to which
the ligand had been degraded.
Integration of the .sup.31P-NMR spectrum indicated that 4% of the
compound (1) had been degraded.
The mixture was subsequently returned to the autoclave, the
autoclave was flushed three times with nitrogen and then maintained
at 120.degree. C. and a nitrogen pressure of 3 bar for 24 hours.
After the end of the reaction time, the autoclave was cooled,
depressurized and a sample for .sup.31P-NMR analysis was taken
under a protective gas atmosphere in order to determine the degree
to which the ligand had been degraded.
Integration of the .sup.31P-NMR spectrum indicated that a total of
23% of the compound (1) had been degraded.
6. Hydroformylation of Trans-2-butene with Addition of
N,N,2,4,6-pentamethylaniline
0.005 g of Rh(CO).sub.2(acac), 0.181 g of the compound (1) and
0.035 g of N,N,2,4,6-pentamethylaniline were dissolved in 10.26 g
of xylene under a protective gas atmosphere and the mixture was
transferred to a 100 ml steel autoclave. The autoclave was
pressurized with 10 bar of CO/H.sub.2 (1:2) and was then heated to
90.degree. C. over a period of 1 hour. The autoclave was then
carefully depressurized to 7 bar at 90.degree. C. and 10.81 g of a
liquefied gas mixture (30% by volume of trans-2-butene and 70% by
volume of isobutane) were injected via a lock by means of
CO/H.sub.2 (1:2) at 12 bar and the pressure was set to 16 bar
(total) by means of CO/H.sub.2 (1:2). During the reaction time of 4
hours, the temperature was kept at 90.degree. C. and the pressure
was maintained at 16 bar (total) by means of CO/H.sub.2 (1:1).
After the end of the reaction, the autoclave was depressurized via
a cold trap and the contents of the autoclave and of the cold trap
were analyzed by gas chromatography in order to determine the
conversion, the yield of pentanals and the proportion of
n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00003 Conversion 29% Yield 28% Proportion of n product
93%
7. Hydroformylation of Trans-2-butene with Addition of
3-methylindole
0.005 g of Rh(CO).sub.2(acac), 0.180 g of the compound (1) and 0.10
g of 3-methylindole were dissolved in 10.14 g of xylene under a
protective gas atmosphere and the mixture was transferred to a 100
ml steel autoclave. The autoclave was pressurized with 10 bar of
CO/H.sub.2 (1:2) and was then heated to 90.degree. C. over a period
of 1 hour. The autoclave was then carefully depressurized to 7 bar
at 90.degree. C. and 10.81 g of a liquefied gas mixture (30% by
volume of trans-2-butene and 70% by volume of isobutane) were
injected via a lock by means of CO/H.sub.2 (1:2) at 12 bar and the
pressure was set to 16 bar (total) by means of CO/H.sub.2 (1:2).
During the reaction time of 4 hours, the temperature was kept at
90.degree. C. and the pressure was maintained at 16 bar (total) by
means of CO/H.sub.2 (1:1). After the end of the reaction, the
autoclave was depressurized via a cold trap and the contents of the
autoclave and of the cold trap were analyzed by gas chromatography
in order to determine the conversion, the yield of pentanals and
the proportion of n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00004 Conversion 33% Yield 32% Proportion of n product
94%
8. Hydroformylation of Trans-2-butene with Addition of
Quinoline
0.005 g of Rh(CO).sub.2(acac), 0.181 g of the compound (1) and
0.029 g of quinoline were dissolved in 10.16 g of xylene under a
protective gas atmosphere and the mixture was transferred to a 100
ml steel autoclave. The autoclave was pressurized with 10 bar of
CO/H.sub.2 (1:2) and was then heated to 90.degree. C. over a period
of 1 hour. The autoclave was then carefully depressurized to 7 bar
at 90.degree. C. and 10.81 g of a liquefied gas mixture (30% by
volume of trans-2-butene and 70% by volume of isobutane) were
injected via a lock by means of CO/H.sub.2 (1:2) at 12 bar and the
pressure was set to 16 bar (total) by means of CO/H.sub.2 (1:2).
During the reaction time of 4 hours, the temperature was kept at
90.degree. C. and the pressure was maintained at 16 bar (total) by
means of CO/H.sub.2 (1:1). After the end of the reaction, the
autoclave was depressurized via a cold trap and the contents of the
autoclave and of the cold trap were analyzed by gas chromatography
in order to determine the conversion, the yield of pentanals and
the proportion of n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00005 Conversion 29% Yield 27% Proportion of n product
90%
9. Hydroformylation of Raffinate II without Additive (Comparative
Example)
0.006 g of Rh(CO).sub.2(acac) and 0.217 g of the compound (1) were
dissolved in 10.0 g of toluene under a protective gas atmosphere
and the mixture was transferred to a 100 ml steel autoclave. The
autoclave was pressurized with 10 bar of CO/H.sub.2 (1:2) and was
then heated to 90.degree. C. over a period of 0.5 hour. The
autoclave was then carefully depressurized to 7 bar at 90.degree.
C. and 10.2 g of a liquefied gas mixture (1.7% of isobutane, 12.4%
of n-butane, 31.7% of trans-2-butene, 35.1% of 1-butene, 2.4% of
isobutene, 16.8% of cis-2-butene) were injected via a lock by means
of CO/H.sub.2 (1:2) at 12 bar and the pressure was set to 17 bar
(total) by means of CO/H.sub.2 (1:2). During the reaction time of 4
hours, the temperature was kept at 90.degree. C. and the pressure
was maintained at 17 bar (total) by means of CO/H.sub.2 (1:1).
After the end of the reaction, the autoclave was depressurized via
a cold trap and the contents of the autoclave and of the cold trap
were analyzed by gas chromatography in order to determine the
conversion, the yield of pentanals and the proportion of
n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00006 Conversion 89% Yield 88% Proportion of n product
95%
10. Hydroformylation of Raffinate II with Addition of
1-H-benzotriazole
0.006 g of Rh(CO).sub.2(acac) and 0.212 g of the compound (1) and
0.014 g of 1-H-benzotriazole were dissolved in 10.1 g of toluene
under a protective gas atmosphere and the mixture was transferred
to a 100 ml steel autoclave. The autoclave was pressurized with 10
bar of CO/H.sub.2 (1:2) and was then heated to 90.degree. C. over a
period of 0.5 hour. The autoclave was then carefully depressurized
to 7 bar at 90.degree. C. and 10.4 g of a liquefied gas mixture
(1.7% of isobutane, 12.4% of n-butane, 31.7% of trans-2-butene,
35.1% of 1-butene, 2.4% of isobutene, 16.8% of cis-2-butene) were
injected via a lock by means of CO/H.sub.2 (1:2) at 12 bar and the
pressure was set to 17 bar (total) by means of CO/H.sub.2 (1:2).
During the reaction time of 4 hours, the temperature was kept at
90.degree. C. and the pressure was maintained at 17 bar (total) by
means of CO/H.sub.2 (1:1). After the end of the reaction, the
autoclave was depressurized via a cold trap and the contents of the
autoclave and of the cold trap were analyzed by gas chromatography
in order to determine the conversion, the yield of pentanals and
the proportion of n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00007 Conversion 88% Yield 87% Proportion of n product
95%
(no significant change compared to comparative example 9) 11.
Degradation Experiment Using 1-H-benzotriazole
0.005 g of Rh(CO).sub.2(acac), 0.181 g of compound (1) and 0.024 g
of 1-H-benzotriazole were dissolved in 8.02 g of Texanole.RTM.
under a protective gas atmosphere and the mixture was transferred
to a 60 ml steel autoclave. The autoclave was pressurized at
25.degree. C. with 20 bar of CO/H.sub.2 (1:1) and then heated to
120.degree. C. over a period of 60 minutes. The autoclave was then
carefully depressurized to 7 bar at 120.degree. C. and 11.23 g of a
liquefied gas mixture (2.9% by volume of isobutane; 14.6% by volume
of n-butane; 27.4% by volume of trans-2-butene; 37.4% by volume of
1-butene; 2.6% by volume of isobutene; 15.3% of cis-2-butene) were
injected via a lock by means of CO/H.sub.2 (1:1) at 12 bar. The
pressure was increased to 28 bar (total) by means of CO/H.sub.2
(1:1) and the autoclave was maintained at 120.degree. C. for 24
hours. After the end of the reaction time, the autoclave was
cooled, depressurized and a sample for .sup.31P-NMR analysis was
taken under a protective gas atmosphere to determine the degree to
which the ligand had been degraded.
Integration of the .sup.31P-NMR spectrum indicated that 3% of the
compound (1) had been degraded.
The mixture was subsequently returned to the autoclave, the
autoclave was flushed three times with nitrogen and then maintained
at 120.degree. C. and a nitrogen pressure of 3 bar for 24 hours.
After the end of the reaction time, the autoclave was cooled,
depressurized and a sample for .sup.31P-NMR analysis was taken
under a protective gas atmosphere in order to determine the degree
to which the ligand had been degraded.
Integration of the .sup.31P-NMR spectrum indicated that a total of
29% of the compound (1) had been degraded.
12. Hydroformylation of Raffinate II and Treatment of the Reaction
Product Mixture with an Ion Exchanger
0.0051 g of Rh(CO).sub.2(acac) (acac =acetylacetonate) and 0.1806 g
of ligand (1) were dissolved in 8.05 g of toluene under N.sub.2.
This solution was analyzed by .sup.31P-NMR (see table 1; blank) and
the mixture was transferred to a 100 ml steel autoclave. The
autoclave was pressurized with 20 bar of CO/H.sub.2 (1:1) at
25.degree. C., and then heated to 120.degree. C. and maintained at
this temperature for 30 minutes. The autoclave was subsequently
depressurized to 7 bar and 11.37 g of liquefied gas mixture were
injected via a lock by means of CO/H.sub.2 (1:1) at 12 bar.
The liquefied gas mixture had the following composition (in % by
weight):
TABLE-US-00008 isobutane 2.9% n-butane 14.6% trans-2-butene 27.4%
1-butene 37.4% isobutene 2.6% cis-2-butene 15.3%
The pressure in the autoclave was brought to a total pressure of 28
bar by means of CO/H.sub.2 (1:1) and these conditions were
maintained for 24 hours. The autoclave was subsequently cooled,
depressurized and a sample of the contents of the reactor were
analyzed by .sup.31P-NMR (see table 1). 21.8 g of a yellow,
homogeneous solution were obtained.
The product mixture was stirred with 2 g of Amberlite.RTM. IRA 67
at 25.degree. C. under N.sub.2 for 30 minutes.
A sample of the liquid reaction mixture was subsequently analyzed
by .sup.31P-NMR (see table 1).
TABLE-US-00009 TABLE 1 Results of the .sup.31P-NMR analysis:
Quantitative .sup.31P-NMR analysis Evaluation of the integrals in %
by area Ligand Degradation Sample (1) Oxide (2) Oxide (3) products
Blank 98.6 1.4 After hydroformylation 25.3 7.1 1.5 66.1 After
treatment with 37.3 10.2 3.1 49.4 ion exchanger
The oxidation is caused by sampling. The oxides are to be counted
as ligand:
##STR00020## 13. Continuous Hydroformylation without Stabilization
(Comparative Example)
FIG. 1 shows a miniplant for carrying out continuous
hydroformylations. This consists of two autoclaves with lifting
stirrer connected in series (1 and 2) and having a liquid capacity
of 0.4 l (reactor 1) and 1.9 l (reactor 2), a pressure separator
(3), a flash stripping column (4) operated using nitrogen as
stripping gas for separating off the catalyst-containing
high-boiling phase from the product phase and unreacted
C.sub.4-hydrocarbons and also an ion exchanger bed (5). In this
plant, raffinate II (isobutane 2.4%, n-butane 12.6%, trans-2-butene
31.5%, 1-butene 36.8%, isobutene 1.8%, cis-2-butene 14.9%) was
hydroformylated using rhodium and the ligand from example 1 as
catalyst. The catalyst recycle stream from the flash column (4)
amounted to about 200 g/h and the raffinate II inflow was about 180
g/h. The temperature of the two reactors was 90.degree. C. The
first reactor was operated using synthesis gas having a CO:H.sub.2
molar ratio of 4:6 and at a total pressure of about 17 bar.
Hydrogen was additionally introduced into the second reactor and
the reactor was operated at a total pressure of 16 bar. The CO
content of the offgas was set to 10%. In steady-state operation
over a representative period of eight days, the plant gave an
aldehyde yield of 55%. The ion exchanger (5) was not active in this
experiment. The rhodium concentration in the catalyst recycle
stream from the flash column (4) was about 320 ppm. According to
HPLC analysis, 15 000 ppm of skatOX ligand (1) were present in the
catalyst recycle stream at the beginning of the period of time
under consideration. After six days, only 3100 ppm of skatOX ligand
(1) could be detected by HPLC analysis, and after eight days no
skatOX ligand (1) could be detected.
14. Continuous Hydroformylation with Stabilization by Means of an
Ion Exchanger
FIG. 2 shows a miniplant for carrying out continuous
hydroformylations. This consists of two autoclaves with lifting
stirrer connected in series (1 and 2) and each having a liquid
capacity of 1.9 l, a pressure separator (3), a heated
depressurization vessel for separating off C.sub.4-hydrocarbons
(4), a wiped film evaporator (5) for separating off the
catalyst-containing high-boiling phase from the product phase and
an ion exchanger bed (6). In this plant, raffinate II (isobutane
3.6%, n-butane 13.8%, trans-2-butene 30.9%, 1-butene 32.0%,
isobutene 2.2%, cis-2-butene 17.5%) was hydroformylated using
rhodium and the ligand (1) as catalyst. The catalyst recycle stream
from the distillation (5) amounted to about 250 g/h and the
raffinate II inflow was about 180 g/h. The temperature of the two
reactors was 90.degree. C. The reactors were supplied with
synthesis gas having a CO:H.sub.2 molar ratio of 4:6 and operated
at a total pressure of about 17 bar. In addition, hydrogen was
introduced into the first reactor to set the CO content of the
offgas to 10%. In steady-state operation over a representative
period of 40 days, the plant gave an aldehyde yield of 65%. The
rhodium concentration in the stream from the separator (4) to the
distillation (5) was about 110 ppm. According to HPLC analysis,
7740 ppm of skatOX ligand (1) were present in the stream from the
separator (4) to the distillation (5) at the beginning of the
period of time under consideration. After 40 days, only 2150 ppm of
(1) could be detected.
15. Hydroformylation of Raffinate II with Addition of Bottoms from
a Plant
0.004 g of Rh(CO).sub.2(acac), 0.141 g of compound (1) and 3.71 g
of catalyst-containing bottoms from a continuously operated
miniplant (as described in example 13) were dissolved in 5.8 g of
toluene under a protective gas atmosphere and the mixture was
transferred to a 100 ml steel autoclave.
The bottoms came from the miniplant described in examples 13 and 14
and contained 480 ppm of rhodium and 3800 ppm of phosphorus. The
autoclave was pressurized with 10 bar of CO/H.sub.2 (1:2) at
25.degree. C. and was then heated to 90.degree. C. over a period of
30 minutes. The autoclave was then carefully depressurized at
90.degree. C. and 11.6 g of a liquefied gas mixture (2.9% by volume
of isobutane; 14.6% by volume of n-butane; 27.4% by volume of
trans-2-butene; 37.4% by volume of 1-butene; 2.6% by volume of
isobutene; 15.3% of cis-2-butene) were injected via a lock by means
of CO/H.sub.2 (1:1) at 8 bar. The pressure was increased to 17 bar
(total) by means of CO/H.sub.2 (1:1) and the autoclave was
maintained at 90.degree. C. for 6 hours. After the end of the
reaction, the autoclave was depressurized via a cold trap and the
contents of the autoclave and of the cold trap were analyzed by gas
chromatography in order to determine the conversion, the yield of
pentanals and the proportion of n-valeraldehyde among the
pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00010 Conversion 65% Yield 59% Proportion of n product
90.7%
16. Hydroformylation of Raffinate II with Addition of Bottoms from
a Plant Washing with Water
0.004 g of Rh(CO).sub.2(acac), 0.130 g of compound (1) and 5.37 g
of catalyst-containing bottoms from a continuously operated
miniplant (as described in example 13) were dissolved in 5.37 g of
toluene under a protective gas atmosphere and the mixture was
transferred to a 100 ml steel autoclave.
The bottoms came from the miniplant described in examples 13 and 14
and contained 480 ppm of rhodium and 3800 ppm of phosphorus. The
bottoms were shaken with water under a protective gas atmosphere
before use in the experiment. The autoclave was pressurized with 10
bar of CO/H.sub.2 (1:2) at 25.degree. C. and was then heated to
90.degree. C. over a period of 30 minutes. The autoclave was then
carefully depressurized at 90.degree. C. and 9.8 g of a liquefied
gas mixture (2.9% by volume of isobutane; 14.6% by volume of
n-butane; 27.4% by volume of trans-2-butene; 37.4% by volume of
1-butene; 2.6% by volume of isobutene; 15.3% of cis-2-butene) were
injected via a lock by means of CO/H.sub.2 (1:1) at 8 bar. The
pressure was increased to 17 bar (total) by means of CO/H.sub.2
(1:1) and the autoclave was maintained at 90.degree. C. for 6
hours. After the end of the reaction, the autoclave was
depressurized via a cold trap and the contents of the autoclave and
of the cold trap were analyzed by gas chromatography in order to
determine the conversion, the yield of pentanals and the proportion
of n-valeraldehyde among the pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00011 Conversion 66% Yield 60% Proportion of n product
90.8%
17. Hydroformylation of Raffinate II with Addition of Bottoms from
a Plant Washing with Aqueous NaHCO.sub.3 Solution
0.003 g of Rh(CO).sub.2(acac), 0.104 g of compound (1) and 2.73 g
of catalyst-containing bottoms from a continuously operated
miniplant (as described in example 13) were dissolved in 4.27 g of
toluene under a protective gas atmosphere and the mixture was
transferred to a 100 ml steel autoclave.
The bottoms came from the miniplant described in examples 13 and 14
and contained 480 ppm of rhodium and 3800 ppm of phosphorus. The
bottoms were shaken with aqueous NaHCO.sub.3 solution under a
protective gas atmosphere before use in the experiment. The
autoclave was pressurized with 10 bar of CO/H.sub.2 (1:2) at
25.degree. C. and was then heated to 90.degree. C. over a period of
30 minutes. The autoclave was then carefully depressurized at
90.degree. C. and 10.6 g of a liquefied gas mixture (2.9% by volume
of isobutane; 14.6% by volume of n-butane; 27.4% by volume of
trans-2-butene; 37.4% by volume of 1-butene; 2.6% by volume of
isobutene; 15.3% of cis-2-butene) were injected via a lock by means
of CO/H.sub.2 (1:1) at 8 bar. The pressure was increased to 17 bar
(total) by means of CO/H.sub.2 (1:1) and the autoclave was
maintained at 90.degree. C. for 6 hours. After the end of the
reaction, the autoclave was depressurized via a cold trap and the
contents of the autoclave and of the cold trap were analyzed by gas
chromatography in order to determine the conversion, the yield of
pentanals and the proportion of n-valeraldehyde among the
pentanals.
Results of the analysis by gas chromatography:
TABLE-US-00012 Conversion 68% Yield 62% Proportion of n product
91.7%
* * * * *